New developments in our understanding of vitamin metabolism, action and treatment

Decreased circulating IPA levels identify subjects with metabolic comorbidities: A multi-omics study

In recent years several experimental observations demonstrated that the gut microbiome plays a role in regulating positively or negatively metabolic homeostasis. Indole-3-propionic acid (IPA), a Tryptophan catabolic product mainly produced by C. Sporogenes, has been recently shown to exert either favorable or unfavorable effects in the context of metabolic and cardiovascular diseases. We performed a study to delineate clinical and multiomics characteristics of human subjects characterized by low and high IPA levels. Subjects with low IPA blood levels showed insulin resistance, overweight, low-grade inflammation, and features of metabolic syndrome compared to those with high IPA. Metabolomics analysis revealed that IPA was negatively correlated with leucine, isoleucine, and valine metabolism. Transcriptomics analysis in colon tissue revealed the enrichment of several signaling, regulatory, and metabolic processes. Metagenomics revealed several OTU of ruminococcus, alistipes, blautia, butyrivibrio and akkermansia were significantly enriched in highIPA group while in lowIPA group Escherichia-Shigella, megasphera, and Desulfovibrio genus were more abundant. Next, we tested the hypothesis that treatment with IPA in a mouse model may recapitulate the observations of human subjects, at least in part. We found that a short treatment with IPA (4 days at 20/mg/kg) improved glucose tolerance and Akt phosphorylation in the skeletal muscle level, while regulating blood BCAA levels and gene expression in colon tissue, all consistent with results observed in human subjects stratified for IPA levels. Our results suggest that treatment with IPA may be considered a potential strategy to improve insulin resistance in subjects with dysbiosis.

Effect of 2 dosages of prepartum cholecalciferol injection on blood minerals, vitamin D metabolites, and milk production in multiparous dairy cows: A randomized clinical trial

The objective of the present study was to evaluate the effect of 2 dosages of prepartum cholecalciferol injection on blood minerals, vitamin D metabolites, and milk production. Cows entering their second or greater lactation (n = 158) were randomly assigned to a control group (CON) or one of 2 treatment groups receiving either 6 × 106 IU (6VitD) or 12 × 106 IU (12VitD) cholecalciferol intramuscularly on d 275 ± 1.2 (SD) of gestation. Concentrations of serum total Ca (tCa), phosphate, and Mg were determined on 1, 2, 3, 5, 7, and 10 d in milk (DIM). For a subsample of 30 cows entering the third lactation (n = 10/group), these samples were analyzed for cholecalciferol, 25-hydroxycholecalciferol (25-OHD3), and 24,25-dihydroxycholecalciferol (24,25-[OH]2D3). In these cows, we also determined 1,25-dihydroxycholecalciferol (1,25-[OH]2D3), the biologically most active metabolite, on 1, 2, 3, and 5 DIM. Repeated measures ANOVA was performed to evaluate the effect of different dosages of cholecalciferol on blood minerals, vitamin D metabolites, and milk yield over the first 5 test days after calving. Binary outcomes such as retained placenta and metritis were analyzed using a chi-squared test. Although the 12VitD treatment increased tCa concentrations on 1, 2, and 3 DIM compared with CON, administration of 6VitD increased tCa concentrations only on 1 DIM. Compared with CON cows and 6VitD cows, 12VitD cows had greater serum phosphate concentration during the first 10 DIM. Furthermore, 6VitD cows had greater serum phosphate concentrations compared with CON cows. On the contrary, 12VitD cows had lower serum Mg concentrations during the first 10 DIM compared with CON and 6VitD cows. Cholecalciferol was increased by the treatment and decreased quickly until 10 DIM. In respect to 25-OHD3, the 6VitD treatment resulted in a 4.1-fold increase in comparison to the CON group, while a 6.5-fold increase was observed in 12VitD animals. The vitamin D metabolite 24,25-(OH)2D3 increased linearly with 25-OHD3 serum levels, resulting in the highest concentrations in the 12VitD group. An increase of 1,25-(OH)2D3 until 3 DIM was observed in all cows. However, this rise was most pronounced in the CON group. The incidence of retained placenta was 1.9%, 11.5%, and 29.6%, and that of metritis was 11.5%, 15.4%, and 31.5% for CON, 6VitD, and 12VitD cows, respectively. Although none of the treated cows exerted clinical signs of hypocalcemia, one cow in CON incurred clinical hypocalcemia. Cows of the 12VitD group had a lower milk yield over the first 5 monthly test days compared with the control and 6VitD group (42.2 ± 0.5, 42.0, ± 0.5 and 40.7 ± 0.5 kg for control cows, 6VitD cows and 12VitD cows, respectively). Although no negative side effects were observed in 6VitD cows, we do not recommend the general application of 6 × 106 IU cholecalciferol before calving as positive effects on calcium homeostasis were marginal and restricted to the first DIM. The present findings confirm that the application of 12 × 106 IU cholecalciferol negatively affected milk production on this farm.

The rs11568820 Variant in the Promoter Region of Vitamin D Receptor Gene Is Associated with Clinical Remission in Rheumatoid Arthritis Patients Receiving Tumor Necrosis Factor Inhibitors

The vitamin D receptor (VDR), binding to the active form of the vitamin, promotes the transcription of numerous genes involved in the proliferation of immune cells, cytokine production and lymphocyte activation. It is known that vitamin D deficiency can influence the risk of developing rheumatoid arthritis (RA) or modulate its disease activity. The aim of this study was to investigate a possible association between the rs11568820 (C > T) polymorphism in the promoter region of VDR gene and the response to therapy with anti-TNF drugs in patients with RA. A total of 178 consecutive Italian patients with RA treated with anti-TNF, naïve for biological therapy, were recruited. Disease activity data were evaluated using specific indices such as DAS28, CDAI and SDAI, measured at the start of therapy and subsequently at 22, 52, 104 and 240 weeks. A statistically significant association emerged between the rs11568820 variant allele of VDR gene and failure to remission assessed by CDAI and SDAI at 52 weeks, and by DAS28, CDAI and SDAI at 104 weeks of follow-up. Furthermore, the variant allele of this polymorphism was observed more frequently in patients who did not undergo sustained remission calculated by CDAI and SDAI. The variant T allele of rs11568820 in VDR gene is associated with a reduced remission rate with anti-TNFα drugs. These data suggest the role of VDR genetic variability in the response to therapy and in the achievement of remission.

Relationship of the bone phenotype of the Klotho mutant mouse model of accelerated aging to changes in skeletal architecture that occur with chronological aging

Introduction

Due to the relatively long life span of rodent models, in order to expediate the identification of novel therapeutics of age related diseases, mouse models of accelerated aging have been developed. In this study we examined skeletal changes in the male and female Klotho mutant (kl/kl) mice and in male and female chronically aged mice to determine whether the accelerated aging bone phenotype of the kl/kl mouse reflects changes in skeletal architecture that occur with chronological aging.

Methods

2, 6 and 20-23 month old C57BL/6 mice were obtained from the National Institute of Aging aged rodent colony and wildtype and kl/kl mice were generated as previously described by M. Kuro-o. Microcomputed tomography analysis was performed ex vivo to examine trabecular and cortical parameters from the proximal metaphyseal and mid-diaphyseal areas, respectively. Serum calcium and phosphate were analyzed using a colorimetric assay. The expression of duodenal Trpv6, which codes for TRPV6, a vitamin D regulated epithelial calcium channel whose expression reflects intestinal calcium absorptive efficiency, was analyzed by quantitative real-time PCR.

Results and discussion

Trabecular bone volume (BV/TV) and trabecular number decreased continuously with age in males and females. In contrast to aging mice, an increase in trabecular bone volume and trabecular number was observed in both male and female kl/kl mice. Cortical thickness decreased with advancing age and also decreased in male and female kl/kl mice. Serum calcium and phosphate levels were significantly increased in kl/kl mice but did not change with age. Aging resulted in a decline in Trpv6 expression. In the kl/kl mice duodenal Trpv6 was significantly increased. Our findings reflect differences in bone architecture as well as differences in calcium and phosphate homeostasis and expression of Trpv6 between the kl/kl mutant mouse model of accelerated aging and chronological aging. Although the Klotho deficient mouse has provided a new understanding of the regulation of mineral homeostasis and bone metabolism, our findings suggest that changes in bone architecture in the kl/kl mouse reflect in part systemic disturbances that differ from pathophysiological changes that occur with age including dysregulation of calcium homeostasis that contributes to age related bone loss.

Vitamin D and cancer

The role of vitamin D in the prevention of chronic diseases including cancer, has received a great deal of attention during the past few decades. The term "Cancer" represents multiple disease states with varying biological complexities. The strongest link between vitamin D and cancer is provided by ecological and studies like observational, in preclinical models. It is apparent that vitamin D exerts diverse biological responses in a tissue specific manner. Moreover, several human factors could affect bioactivity of vitamin D. The mechanism(s) underlying vitamin D initiated anti-carcinogenic effects are diverse and includes changes at the muti-system levels. The oncogenic environment could easily corrupt the traditional role of vitamin D or could ensure resistance to vitamin D mediated responses. Several researchers have identified gaps in our knowledge pertaining to the role of vitamin D in cancer. Further areas are identified to solidify the role of vitamin D in cancer control strategies.

Plasma 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D Levels in Breast Cancer Risk in Mali: A Case-Control Study

(1) Background: Breast cancer is the most prevalent cancer found in women in Mali. The aim of the current study was to determine the association between metabolites circulating in the blood, 25(OH)D and 1,25(OH)2D, and vitamin D levels with the risk of breast cancer in Malian women. (2) Methods: We conducted a prospective case-control study from August 2021 to March 2022. Control subjects were matched to cases according to age (within 5 years). The patients' clinical stage was determined by the oncologist according to the tumour-nodes-metastasis (TNM) classification system. (3) Results: We observed no differences in the mean 25(OH)D (p = 0.221) and 1,25(OH)2D (p = 0.285) between cases and controls. However, our findings indicate a more pronounced inverse association in the first level of plasma 25(OH)D, while the risk function decreases at higher levels. This observation takes strength with 1,25(OH)2D by a significant association between the first quartile and breast cancer as a risk factor (p = 0.03; OR = 71.84; CI: 1.36-3785.34). (4) Conclusions: These outcomes showed a possible association between 25(OH)D and 1,25(OH)2D in decreasing the risk of breast cancer.

Determination of vitamin D status in singleton and twin gestations using CLIA and LC-MS/MS

Objective

Vitamin D plays an important role during pregnancy. The aim was to compare vitamin D status in a group of singleton (SP) and twin pregnancies (TP) using two diagnostic methods: chemiluminescence immunoassay (CLIA) and liquid chromatography with tandem mass spectrometry (LC-MS/MS).

Design

This is a cross-sectional study.

Methods

The study was conducted in the population of SP and TP at the gestational age above 20 + 0 at the Bielanski Hospital in Warsaw, Poland, between October 2020 and January 2023. All patients had their venous blood samples collected and were given an original survey containing questions on demography and vitamin D supplementation.

Results

The study group included 53 Caucasian women with SP and 78 with TP aged from 21 to 47. Considering LC-MS/MS, patients with TP had lower concentrations of 25-hydroxyvitamin D (25(OH)D) than patients with SP. However, no significant difference was observed in the frequency of the occurrence of vitamin D deficiency (25(OH)D < 30 ng/mL). In both groups, the levels obtained with CLIA were significantly lower than in case of LC-MS/MS, however, strongly correlated. The intermethod agreement accounted for 52.4% and the Cohen's kappa coefficient was 0.142.

Conclusions

The concentration of 25(OH)D in pregnant women depends on the type of gestation (SP/TP) and on the diagnostic methods used (CLIA/LC-MS/MS). Based on LC-MS/MS, the incidence of vitamin D deficiency was low in our group and no differences occurred in its frequency between SP and TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low.

Significance statement

This is the first study to compare the concentration of 25(OH)D levels between SP and TP using two methods: CLIA and the gold standard - LC-MS/MS. Based on LC-MS/MS, a low incidence of vitamin D deficiency was observed in our group, in which the vast majority of patients took cholecalciferol supplements. Moreover, there were no differences in its frequency between SP and TP. However, the 25(OH)D level was significantly lower in TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low, which is associated with substantial clinical implications.

Assessment, treatment and prevention of vitamin D deficiency

Vitamin D deficiency is prevalent among various groups in the UK, and can result from insufficient sunlight exposure and dietary intake. There is a population-wide recommendation of 10 micrograms (400 international units) of vitamin D per day, with a daily supplement advised. However, supplement use is often suboptimal, compounding the risk of deficiency. Long-term vitamin D deficiency can cause rickets in children and osteomalacia or osteoporosis in adults. Therefore, it is important that nurses recognise which groups are at increased risk of vitamin D deficiency and understand how to assess people's vitamin D status. Nurses also need to be able to support the prevention and treatment of low vitamin D levels, which typically involves supplementation and lifestyle changes.

Enzymatic activation in vitamin D signaling - Past, present and future

Vitamin D signaling is important in regulating calcium homeostasis essential for bone health but also displays other functions in cells of several tissues. Disturbed vitamin D signaling is linked to a large number of diseases. The multiple cytochrome P450 (CYP) enzymes catalyzing the different hydroxylations in bioactivation of vitamin D₃ are crucial for vitamin D signaling and function. This review is focused on the progress achieved in identification of the bioactivating enzymes and their genes in production of 1α,25-dihydroxyvitamin D₃ and other active metabolites. Results obtained on species- and tissue-specific expression, catalytic reactions, substrate specificity, enzyme kinetics, and consequences of gene mutations are evaluated. Matters of incomplete understanding regarding the physiological roles of some vitamin D hydroxylases are critically discussed and the authors will give their view of the importance of each enzyme for vitamin D signaling. Roles of different vitamin D receptors and an alternative bioactivation pathway, leading to 20-hydroxylated vitamin D₃ metabolites, are also discussed. Considerable progress has been achieved in knowledge of the vitamin D₃ bioactivating enzymes. Nevertheless, several intriguing areas deserve further attention to understand the pleiotropic and diverse activities elicited by vitamin D signaling and the mechanisms of enzymatic activation necessary for vitamin D-induced responses.

Vitamin D and Autoimmune Rheumatic Diseases

Vitamin D is a steroid hormone with potent immune-modulating properties. It has been shown to stimulate innate immunity and induce immune tolerance. Extensive research efforts have shown that vitamin D deficiency may be related to the development of autoimmune diseases. Vitamin D deficiency has been observed in patients with rheumatoid arthritis (RA) and has been shown to be inversely related to disease activity. Moreover, vitamin D deficiency may be implicated in the pathogenesis of the disease. Vitamin D deficiency has also been observed in patients with systemic lupus erythematosus (SLE). It has been found to be inversely related to disease activity and renal involvement. In addition, vitamin D receptor polymorphisms have been studied in SLE. Vitamin D levels have been studied in patients with Sjogren's syndrome, and vitamin D deficiency may be related to neuropathy and the development of lymphoma in the context of Sjogren's syndrome. Vitamin D deficiency has been observed in ankylosing spondylitis, psoriatic arthritis (PsA), and idiopathic inflammatory myopathies. Vitamin D deficiency has also been observed in systemic sclerosis. Vitamin D deficiency may be implicated in the pathogenesis of autoimmunity, and it may be administered to prevent autoimmune disease and reduce pain in the context of autoimmune rheumatic disorders.

Vitamin D: marker, measurand & measurement

The measurement of vitamin D metabolites aids in assessing vitamin D status and in diagnosing disorders of calcium homeostasis. Most laboratories measure total 25-hydroxyvitamin D (25(OH)D), while others have taken the extra effort to measure 25(OH)D2 and 25(OH)D3 separately and additional metabolites such as 1,25-dihydroxyvitamin D and 24,25-dihydroxyvitamin D. The aim of this review is to provide an updated overview of the main markers of vitamin D metabolism, define the intended measurands, and discuss the advantages and disadvantages of the two most widely used assays, automated assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Whether using the easy and fast automated assays or the more complex LC-MS/MS, one should know the pitfalls of the used technique in order to interpret the measurements. In conclusion, automated assays are unable to accurately measure 25(OH)D in all patient groups, including persons using D2. In these cases, an LC-MS/MS method, when appropriately developed and standardized, produces a more reliable measurement.

Long-Term Safety and Efficacy of Recombinant Human Parathyroid Hormone (1-84) in Adults With Chronic Hypoparathyroidism

Context

Chronic hypoparathyroidism is conventionally treated with oral calcium and active vitamin D to reach and maintain targeted serum calcium and phosphorus levels, but some patients remain inadequately controlled.

Objective

To assess long-term safety and efficacy of recombinant human parathyroid hormone (1-84) (rhPTH(1-84)) treatment.

Methods

This was an open-label extension study at 12 US centers. Adults (n = 49) with chronic hypoparathyroidism were included. The intervention was rhPTH(1-84) for 6 years. The main outcome measures were safety, biochemical measures, oral supplement doses, bone indices.

Results

Thirty-eight patients (77.6%) completed the study. Throughout 72 months, mean albumin-adjusted serum calcium was within 2.00 to 2.25 mmol/L (8.0-9.0 mg/dL). At baseline, 65% of patients with measurements (n = 24/37) were hypercalciuric; of these, 54% (n = 13/24) were normocalciuric at month 72. Mean serum phosphorus declined from 1.6 ± 0.19 mmol/L at baseline (n = 49) to 1.3 ± 0.20 mmol/L at month 72 (n = 36). Mean estimated glomerular filtration rate was stable. rhPTH(1-84)-related adverse events were reported in 51.0% of patients (n = 25/49); all but 1 event were mild/moderate in severity. Mean oral calcium supplementation reduced by 45% ± 113.6% and calcitriol by 74% ± 39.3%. Bone turnover markers declined by month 32 to a plateau above pretreatment values; only aminoterminal propeptide of type 1 collagen remained outside the reference range. Mean bone mineral density z score fell at one-third radius and was stable at other sites.

Conclusion

6 years of rhPTH(1-84) treatment was associated with sustained improvements in biochemical parameters, a reduction in the percentage of patients with hypercalciuria, stable renal function, and decreased supplement requirements. rhPTH(1-84) was well tolerated; no new safety signals were identified.

Vitamin D: review of physiology and clinical uses

Interest in vitamin D has increased within the scientific community due to the impact of osteoporosis in the aging population. Vitamin D receptors are present in many tissues and low vitamin D status has been associated with many diseases in observational studies. There was hope that enhanced vitamin D provision might help prevent and treat some widespread disorders. Some of these hopes have been refuted by the results of recent large and well-conducted randomized trials. This review provides an overview of the basic physiology of vitamin D and an update on the evidence base for its clinical applications.

Vitamin D, Gut Microbiota, and Cardiometabolic Diseases-A Possible Three-Way Axis

Metabolic syndrome (MetSyn) is a precursor for several cardiometabolic diseases such as obesity, type-2 diabetes mellitus (T2DM), and cardiovascular diseases. Emerging evidence suggests that vitamin D deficiency links to cardiometabolic diseases through microbiota. A combination of poor vitamin D status and dysbiosis may contribute to the progression of cardiometabolic diseases. Therefore, in this review, we present the relationship among vitamin D, microbiota, and cardiometabolic diseases with a focus on MetSyn. We searched major databases for reports on vitamin D, microbiota, and MetSyn until June 2022. We reviewed 13 reports on the relation between vitamin D and MetSyn (6 randomized controlled and 7 cross-sectional studies) and 6 reports on the effect of vitamin D on the gut microbiome. Adequate vitamin D status has a beneficial effect on gut microbiota, therefore preventing the progression of MetSyn. Further, well-controlled studies are needed for a better understanding of the mechanisms of action involving vitamin D and microbiota in the pathogenesis of cardiometabolic diseases.

Effect of vitamin D metabolites on bone histomorphometry in healthy black and white women: An attempt to unravel the so-called vitamin D paradox in blacks

An apparent vitamin D paradox, characterized by lower serum 25-hydroxyvitamin D (25(OH)D) levels and higher bone mineral density, is present in black population. In contrast, blacks have higher serum 1,25-dihydroxyvitamin D (1,25(OH)₂D) levels. The effect of 1,25(OH)₂D on the skeleton is not fully understood. We examined serum 25(OH)D, 1,25(OH)₂D and bone histomorphometry in 50 black and white women (25 each) matched for age, menstrual status, and BMI. Histomorphometric indices related to bone structure, remodeling and mineralization were measured in cancellous bone in iliac bone biopsies. Data analyses led to the following results: 1) serum 25(OH)D was significantly lower and 1,25(OH)₂D was significantly higher in black than in white women, but neither blacks nor whites revealed significant correlation between these two vitamin D metabolites. 2) there was no significant difference in PTH levels between blacks and whites. 3) except for greater trabecular thickness (Tb.Th) in blacks, there were no significant differences in other histomorphometric variables between the two ethnic groups. 4) osteoid surface (OS/BS), unlabeled osteoid surface (ulOS/BS), and osteoblast surface (ObS/BS) significantly correlated with serum 1,25(OH)₂D levels. We conclude that lower serum 25(OH)D levels in blacks do not impair bone structure and remodeling, nor decrease bone mineralization. Higher serum 1,25(OH)₂D levels in blacks may help preserve bone mass by stimulating bone formation via increasing osteoblast number and function, but moderately inhibit terminal bone mineralization as shown by higher ulOS/BS.

Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites

Vitamin D has a well-known role in the calcium homeostasis associated with the maintenance of healthy bones. It increases the efficiency of the intestinal absorption of dietary calcium, reduces calcium losses in urine, and mobilizes calcium stored in the skeleton. However, vitamin D receptors are present ubiquitously in the human body and indeed, vitamin D has a plethora of non-calcemic functions. In contrast to most vitamins, sufficient vitamin D can be synthesized in human skin. However, its production can be markedly decreased due to factors such as clothing, sunscreens, intentional avoidance of the direct sunlight, or the high latitude of the residence. Indeed, more than one billion people worldwide are vitamin D deficient, and the deficiency is frequently undiagnosed. The chronic deficiency is not only associated with rickets/osteomalacia/osteoporosis but it is also linked to a higher risk of hypertension, type 1 diabetes, multiple sclerosis, or cancer. Supplementation of vitamin D may be hence beneficial, but the intake of vitamin D should be under the supervision of health professionals because overdosing leads to intoxication with severe health consequences. For monitoring vitamin D, several analytical methods are employed, and their advantages and disadvantages are discussed in detail in this review.

Dietary supplementation of 25-hydroxycholecalciferol as an alternative to cholecalciferol in swine diets: A review

25-hydroxycholecalciferol (25-OHD₃ ) formed via hepatic hydroxylation from vitamin D, cholecalciferol, represents the precursor of the biologically active vitamin D hormone, 1,25-dihydroxyvitamin D. Due to a higher absorption rate and the omission of one hydroxylation, dietary supplementation of 25-OHD₃ instead of vitamin D₃ is considered to be more efficient as plasma concentrations of 25-OHD₃ are increased more pronounced. The present review summarises studies investigating potential beneficial effects on mineral homeostasis, bone metabolism, health status and performance in sows, piglets and fattening pigs. Results are inconsistent. While most studies could not demonstrate any or only a slight impact of partial or total replacement of vitamin D₃ by 25-OHD₃ , some experiments indicated that 25-OHD₃ might alter physiological processes when animals are challenged, for example, by a restricted mineral supply.

Association between serum calcium levels and first stroke: A community-based nested case-control study

Background

Evidence from epidemiologic studies has been limited and inconsistent regarding the role of serum calcium in stroke incidence risk. We aimed to evaluate the association between serum albumin-corrected calcium and the risk of the first stroke in the Chinese community-dwelling population.

Methods

The study sample population was drawn from the “H-type Hypertension and Stroke Prevention and Control Project.” Using a nested case-control study, a total of 1,255 first-stroke cases and 1,255 controls matched for age, sex, and village were included in the final data analysis. We measured the serum calcium by inductively coupled plasma mass spectrometry and assessed the associations between serum albumin-corrected calcium and first stroke using conditional logistic regression.

Results

The overall mean (SD) serum albumin-corrected calcium was 8.9 (0.6) mg/dl. Compared with the middle tertile (8.7–9.1 mg/dl), the multivariate-adjusted odds ratios (95% CIs) of first total stroke associated with the lowest tertile and the highest tertile of serum albumin-corrected calcium were 1.37 (1.10, 1.70) and 1.30 (1.04, 1.62), respectively. Similar trends were observed for the first ischemic stroke. Consistently, restricted cubic spline showed a U-shaped association between serum albumin-corrected calcium and risk of total stroke and ischemic stroke. However, serum albumin-corrected calcium had no significant effect on first hemorrhagic stroke. No significant effect modification was observed in the subgroup analysis.

Conclusions

Our results suggested a U-shaped association between serum calcium and first stroke; both low and high serum calcium levels were associated with an increased risk of the first stroke in the Chinese population.

Metabolic properties of irisin in health and in diabetes mellitus

Irisin is a polypeptide hormone of muscle tissue (myokine), the synthesis and secretion of which increase against the background of physical exertion, which plays a significant role in the metabolism of fat, muscle and bone tissues. It is known that irisin promotes the transformation of white adipose tissue into brown adipose tissue. It has also been experimentally proven that the introduction of irisin contributed to an increase in bone mass and the prevention of osteoporosis and muscular atrophy. There are works indicating a positive effect of irisin in the functioning of bone, fat and muscle tissues in humans. Diabetes mellitus (DM) is an independent risk factor for osteoporotic fractures and the development of specific diabetic myopathy, at the cellular level similar to the aging of muscle tissue, and type 2 diabetes is also associated with the presence of obesity. Thus, it is of particular interest to study the effect of irisin on the state of bone, muscle and adipose tissues and glucose homeostasis in patients with diabetes. This literature review highlights the biological functions of irisin in healthy people and patients with DM.

CYP11A1‑derived vitamin D hydroxyderivatives as candidates for therapy of basal and squamous cell carcinomas

Hydroxyderivatives of vitamin D3, including classical 1,25(OH)2D3 and novel CYP11A1‑derived hydroxyderivatives, exert their biological activity by acting as agonists on the vitamin D receptor (VDR) and inverse agonists on retinoid‑related orphan receptors (ROR)α and γ. The anticancer activities of CYP11A1‑derived hydroxyderivatives were tested using cell biology, tumor biology and molecular biology methods in human A431 and SCC13 squamous (SCC)‑ and murine ASZ001 basal (BCC)‑cell carcinomas, in comparison with classical 1,25(OH)2D3. Vitamin D3‑hydroxyderivatives with or without a C1α(OH) inhibited cell proliferation in a dose‑dependent manner. While all the compounds tested had similar effects on spheroid formation by A431 and SCC13 cells, those with a C1α(OH) group were more potent in inhibiting colony and spheroid formation in the BCC line. Potent anti‑tumorigenic activity against the BCC line was exerted by 1,25(OH)2D3, 1,20(OH)2D3, 1,20,23(OH)3D3, 1,20,24(OH)3D3, 1,20,25(OH)3D3 and 1,20,26(OH)3D3, with smaller effects seen for 25(OH)D3, 20(OH)D3 and 20,23(OH)2D3. 1,25(OH)2D3, 1,20(OH)2D3 and 20(OH)D3 inhibited the expression of GLI1 and β‑catenin in ASZ001 cells. In A431 cells, these compounds also decreased the expression of GLI1 and stimulated involucrin expression. VDR, RORγ, RORα and CYP27B1 were detected in A431, SCC13 and ASZ001 lines, however, with different expression patterns. Immunohistochemistry performed on human skin with SCC and BCC showed nuclear expression of all three of these receptors, as well as megalin (transmembrane receptor for vitamin D‑binding protein), the level of which was dependent on the type of cancer and antigen tested in comparison with normal epidermis. Classical and CYP11A1‑derived vitamin D3‑derivatives exhibited anticancer‑activities on skin cancer cell lines and inhibited GLI1 and β‑catenin signaling in a manner that was dependent on the position of hydroxyl groups. The observed expression of VDR, RORγ, RORα and megalin in human SCC and BCC suggested that they might provide targets for endogenously produced or exogenously applied vitamin D hydroxyderivatives and provide excellent candidates for anti‑cancer therapy.

Metabolic activation of tachysterol3 to biologically active hydroxyderivatives that act on VDR, AhR, LXRs, and PPARγ receptors

CYP11A1 and CYP27A1 hydroxylate tachysterol3 , a photoproduct of previtamin D3 , producing 20S-hydroxytachysterol3 [20S(OH)T3 ] and 25(OH)T3 , respectively. Both metabolites were detected in the human epidermis and serum. Tachysterol3 was also detected in human serum at a concentration of 7.3 ± 2.5 ng/ml. 20S(OH)T3 and 25(OH)T3 inhibited the proliferation of epidermal keratinocytes and dermal fibroblasts and stimulated the expression of differentiation and anti-oxidative genes in keratinocytes in a similar manner to 1,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ]. They acted on the vitamin D receptor (VDR) as demonstrated by image flow cytometry and the translocation of VDR coupled GFP from the cytoplasm to the nucleus of melanoma cells, as well as by the stimulation of CYP24A1 expression. Functional studies using a human aryl hydrocarbon receptor (AhR) reporter assay system revealed marked activation of AhR by 20S(OH)T3 , a smaller effect by 25(OH)T3 , and a minimal effect for their precursor, tachysterol3 . Tachysterol3 hydroxyderivatives showed high-affinity binding to the ligan-binding domain (LBD) of the liver X receptor (LXR) α and β, and the peroxisome proliferator-activated receptor γ (PPARγ) in LanthaScreen TR-FRET coactivator assays. Molecular docking using crystal structures of the LBDs of VDR, AhR, LXRs, and PPARγ revealed high docking scores for 20S(OH)T3 and 25(OH)T3 , comparable to their natural ligands. The scores for the non-genomic-binding site of the VDR were very low indicating a lack of interaction with tachysterol3 ligands. Our identification of endogenous production of 20S(OH)T3 and 25(OH)T3 that are biologically active and interact with VDR, AhR, LXRs, and PPARγ, provides a new understanding of the biological function of tachysterol3 .

The Burden of Cancer, Government Strategic Policies, and Challenges in Pakistan: A Comprehensive Review

Cancer is a severe condition characterized by uncontrolled cell division and increasing reported mortality and diagnostic cases. In 2040, an estimated 28.4 million cancer cases are expected to happen globally. In 2020, an estimated 19.3 million new cancer cases (18.1 million excluding non-melanoma skin cancer) had been diagnosed worldwide, with around 10.0 million cancer deaths. Breast cancer cases have increased by 2.26 million, lung cancer by 2.21 million, stomach by 1.089 million, liver by 0.96 million, and colon cancer by 1.93 million. Cancer is becoming more prevalent in Pakistan, with 19 million new cancer cases recorded in 2020. Food adulteration, gutkha, paan, and nutritional deficiencies are major cancer risk factors that interplay with cancer pathogenesis in this country. Government policies and legislation, cancer treatment challenges, and prevention must be revised seriously. This review presents the current cancer epidemiology in Pakistan to better understand cancer basis. It summarizes current cancer risk factors, causes, and the strategies and policies of the country against cancer.

Dietary vitamin D3 deprivation suppresses fibroblast growth factor 23 signals by reducing serum phosphorus levels in laying hens

The present study was carried out to evaluate the effect of dietary supplemental vitamin D₃ on fibroblast growth factor 23 (FGF23) signals as well as phosphorus homeostasis and metabolism in laying hens. Fourteen 40-week-old Hy-Line Brown layers were randomly assigned into 2 treatments: 1) vitamin D₃ restriction group (n = 7) fed 0 IU/kg vitamin D₃ diet, and 2) regular vitamin D₃ group (n = 7) fed 1,600 IU/kg vitamin D₃ diet. The study lasted for 21 d. Serum parameters, phosphorus and calcium excretion status, and tissue expressions of type II sodium-phosphate co-transporters (NPt2), FGF23 signals and vitamin D₃ metabolic regulators were determined. Hens fed the vitamin D₃ restricted diet had decreased serum phosphorus levels (by 31.3%, P = 0.028) when compared to those fed regular vitamin D₃ diet. In response to the decreased serum phosphorus, the vitamin D₃ restricted laying hens exhibited: 1) suppressed kidney expressions of 25-hydroxyvitamin D 1-α-hydroxylase (CYP27B1, by 52.8%, P = 0.036) and 1,25-dihydroxyvitamin D 24-hydroxylase (CYP24A1, by 99.4%, P = 0.032); 2) suppressed serum levels of FGF23 (by 14.6%, P = 0.048) and increased serum alkaline phosphatase level (by 414.1%, P = 0.012); 3) decreased calvaria mRNA expressions of fibroblast growth factor receptors (FGFR1, by 85.2%, P = 0.003, FGFR2, by 89.4%, P = 0.014, FGFR3, by 88.8%, P = 0.017, FGFR4, by 89.6%, P = 0.030); 4) decreased kidney mRNA expressions of FGFR1 (by 65.5%, P = 0.021), FGFR4 (by 66.0%, P = 0.050) and KLOTHO (by 68.8%, P = 0.038); 5) decreased kidney protein expression of type 2a sodium-phosphorus co-transporters (by 54.3%, P = 0.039); and 6) increased percent excreta calcium (by 26.9%, P = 0.002). In conclusion, the deprivation of dietary vitamin D₃ decreased FGF23 signals in laying hens by reducing serum FGF23 level and suppressing calvaria and kidney mRNA expressions of FGF23 receptors.

Vitamin D Supplementation Improves Mitochondrial Function and Reduces Inflammation in Placentae of Obese Women

Background

About 30% of women entering pregnancy in the US are obese. We have previously reported mitochondrial dysregulation and increased inflammation in the placentae of obese women. Vitamin D (VitD) is a major player in calcium uptake and was shown to modulate mitochondrial respiration and the immune/inflammation system. Studies show decreased VitD levels in obese individuals; however, the effect of maternal obesity on VitD metabolism and its association with placental function remains understudied.

Methods

Maternal and cord blood plasma and placental samples were collected upon C-section from normal-weight (NW, body mass index [BMI]<25) and obese (OB, BMI>30) women with uncomplicated pregnancies at term. We measured 25(OH)D3 (calcidiol) levels in maternal and cord blood plasma using ELISA. We assessed the expression of CYP27B1, an activator of calcidiol, and Vitamin D receptor (VDR) in placentae from NW and OB, and women with gestational diabetes and preeclampsia. In addition, we examined the effects of VitD supplementation on mitochondrial function and inflammation in trophoblasts from NW and OB, using the Seahorse Bioanalyzer and Western blot, respectively.

Results

Vitamin D levels in blood from OB but not NW women and in cord blood from babies born to NW and OB women showed a significant inverse correlation with maternal pre-pregnancy BMI (r=-0.50, p<0.1 and r=-0.55, p=0.004 respectively). Cord plasma VitD levels showed a positive correlation with placental efficiency, i.e., the ratio between fetal and placental weight, as well as with maternal blood VitD levels (r=0.69 and 0.83 respectively, p<0.00). While we found no changes in CYP27B1 in OB vs. NW women, VDR expression were decreased by 50% (p<0.03) independent of fetal sex. No changes in VDR expression relative to BMI-matched controls were observed in the placentae of women with gestational diabetes or preeclampsia. Cytotrophoblasts isolated from placentae of OB women showed a dose-dependent increase in VDR expression after 24-hour treatment with calcitriol (10 nM and 100 nM), an active form of VitD. Trophoblasts isolated from OB women and treated with calcitriol improved mitochondrial respiration (p<0.05). We also found a two-fold increase in expression of the NLRP3 inflammasome and the pro-inflammatory cytokine IL-18 in trophoblasts isolated from placentae of OB women (p<0.05), with IL-18 expression being reversed by calcitriol treatment (100 nM).

Conclusions

We show that VitD deficiency is at least partially responsible for mitochondrial dysfunction and increased inflammation in the placentae of obese women. Vitamin D supplementation could be beneficial in improving placental dysfunction seen in obese women.

What MFTs should know about nutrition, psychosocial health, and collaborative care with nutrition professionals

Despite sufficient evidence on the role of nutrition in psychosocial health, Marriage and Family Therapists lack the knowledge for sufficient assessment and referrals in treatment. The purpose of this article is to orient MFTs to human metabolism and the effects of various nutrients, or lack thereof, on the psychosocial health in their clients. The roles of several micronutrients and macronutrients will be described as well as the effects of eating patterns and overall metabolic health on mental health. Finally, implications for MFTs as sole practitioners, domains for assessment and psychoeducation, and recommendations for collaborating with nutrition professionals will be discussed.

Vitamin D Supplementation and Fractures in Adults: A Systematic Umbrella Review of Meta-Analyses of Controlled Trials

CONTEXT

The growing number of systematic reviews/meta-analyses (SR/MAs) on vitamin D (± calcium) for fracture prevention has led to contradictory guidelines.

OBJECTIVE

This umbrella review aims to assess the quality and explore the reasons for the discrepancy of SR/MAs of trials on vitamin D supplementation for fracture risk reduction in adults.

METHODS

We searched 4 databases (2010-2020), Epistemonikos, and references of included SRs/MAs, and we contacted experts in the field. We used A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR-2) for quality assessment. We compared results and investigated reasons for discordance using matrices and subgroup analyses (PROSPERO registration: CRD42019129540). We included 13 SR/MAs on vitamin D and calcium (Ca/D) and 19 SR/MAs on vitamin D alone, compared to placebo/control.

RESULTS

Only 2 from 10 SRs/MAs on Ca/D were of moderate quality. Ca/D reduced the risk of hip fractures in 8 of 12 SRs/MAs (relative risk [RR] 0.61-0.84), and any fractures in 7 of 11 SR/MAs (RR 0.74-0.95). No fracture risk reduction was noted in SRs/MAs exclusively evaluating community-dwelling individuals or in those on vitamin D alone compared to placebo/control. Discordance in results between SRs/MAs stems from inclusion of different trials, related to search periods and eligibility criteria, and varying methodology (using intention to treat, per-protocol, or complete case analysis from individual trials).

CONCLUSION

Ca/D reduces the risk of hip and any fractures, possibly driven by findings from institutionalized individuals. Individual participant data meta-analyses of patients on Ca/D with sufficient follow-up periods, and subgroup analyses, would unravel determinants for a beneficial response to supplementation.

Analysis of Development Trends of the Research Hotspots of Vitamin D in Children

OBJECTIVE

Using multivariate statistics and social network analysis techniques, we present a realistic and intuitive visualization of the research hotspots and development trends of vitamin D in children.

METHODS

The Medical Subject Headings (MeSH) term "vitamin D" was used to search all the publications (the study subjects were 0-18 years old) included in PubMed by time period. The subject terms for each development stage were extracted, the high-frequency subject terms were extracted using the Bibliographic Items Co-occurrence Matrix Builder (BICOMB), and a core subject term co-occurrence matrix was established. The Netdraw function of Ucinet 6.0 software was used to complete the social network drawing of the core subject term co-occurrence matrix to form a co-word network diagram composed of core subject terms.

RESULTS

Prior to 1979, there were 890 papers with 1,899 core subject terms; from 2010 to 2020, there were 3,773 papers with 12,682 core subject terms. Before 1979, the research direction of vitamin D in children focused on vitamin D in the classical regulation of calcium and phosphorus metabolism. From 1980 to 1989, studies focused on vitamin D metabolites and therapeutic drugs such as "calcitriol" and "calcifediol." From 1990 to 1999, studies focused on "calcitriol" and its association with "psoriasis," "chronic renal failure," and "dermatological drugs." From 2000 to 2009, studies focused on "vitamin D" and "vitamin D deficiency." From 2010 to 2020, studies focused on "vitamin D₃" and its association with "vitamins," "bone mineral density protectants," "asthma," "obesity," "pregnancy complications" and "fetal blood."

CONCLUSION

Since 2010, the research direction of vitamin D in children has been growing rapidly, and the overall development trend is good. Studies extend from the study of the skeletal effect of vitamin D to the study of its extraskeletal effect and the investigation of mechanisms of its association with related diseases.

Vitamin D Dosing: Basic Principles and a Brief Algorithm (2021 Update)

Nowadays, in modern societies, many people can be at high risk to have low vitamin D levels. Therefore, testing of serum 25-hydroxy-vitamin D (25OH-D) levels should be performed before prescribing them vitamin D supplementation. However, in some cases the 25OH-D level assessment is not available at the right moment, e.g., due to mandatory quarantine of COVID-19 outpatients. Therefore, such patients could be advised to start taking moderate vitamin D doses (e.g., 4000 IU/day for adults), and their 25-OH-D levels could be checked later. The proposed algorithm also comprises vitamin D dosing principles when baseline 25OH-D levels are known.

Generic SFC-MS methodology for the quality control of vitamin D3 oily formulations

Vitamin D₃ is a key micronutrient whose intakes are inadequate for most populations worldwide. Supplementation with medicines or food supplements is commonly prescribed to correct this imbalance and the quality of these products must be ensured. In this context, a generic methodology for the assay of vitamin D₃ in oily formulations is proposed using supercritical fluid chromatography coupled to mass spectrometry (SFC-MS). It is in line with green analytical chemistry principles and combines the use of i) a fast and robust analytical method (4.0 min analysis time) ii) an easy sample preparation compatible with high throughput analysis ("dilute-and-shoot" approach) and iii) a relevant control strategy. Seventeen products from multiple manufacturers and encompassing a large content range were evaluated in this study. They were classified in four groups to streamline their processing considering the use of a matrix-matched calibration procedure. Matrix effect was thoroughly studied and was found to be low (99-106%), stable intra/inter-series and comparable between the different groups and types of matrices. The implemented control strategy was based on a three-level system suitability tests (SST). Level 1 SST: resolution of the critical pair that was above 1.5 for all analysis series. Level 2 SST: evaluation of the adequacy of the calibration for a QC sample in terms of recovery that was between 97% and 104% with a variability between 1% and 2%. Level 3 SST: method trueness that was between 95% and 102%. Sample analysis highlighted differences in types of products and dosage forms. This is the first study to propose a complete strategy for the quality control of vitamin D₃ oily formulations and should prove useful in QC laboratories.

A rapid point-of-care assay accurately measures vitamin D

PURPOSE

Vitamin D (VitD) is a pleiotropic hormone with effects on a multitude of systems and metabolic pathways. Consequently, the relevance of a sufficiently high VitD serum level becomes self-evident.

METHODS

A rapid immunofluorescence assay designed for the point-of-care measurement of serum VitD₃ solely was tested. Inter- and intra-assay validation, double testing and result comparison with a standardized laboratory method were performed.

RESULTS

An overall linear correlation of r = 0.89 (Pearson, 95% CI 0.88-0.92, p < 0.01) between the point of care and the conventional reference assay was registered. Accuracy and precision were of special interest at cut-points (10 ng/ml [mean deviation 1.7 ng/ml, SD 1.98 ng/ml, SE 0.16 ng/ml], 12 ng/ml [MD 0.41, SD 1.89, SE 0.19] and 30 ng/ml [MD - 1.11, SD 3.89, SE 0.35]). Only a slight deviation was detected between the two assays when using fresh (r = 0.91, 95% CI 0.86-0.94, p < 0.01) and frozen serum samples (r = 0.86, 0.82-0.89, p < 0.01). Results remained steady when samples were frozen several times. Inter- and intra-assay validation according to the CLSI protocol as well as multiuser testing showed stable results.

CONCLUSION

This novel, innovative, and controlled study indicates that the evaluated rapid point of care VitD assay is reliable, accurate, and suited for clinical practice.

Systemic Jak1 activation causes extrarenal calcitriol production and skeletal alterations provoking stunted growth

Mineral homeostasis is regulated by a complex network involving endocrine actions by calcitriol, parathyroid hormone (PTH), and FGF23 on several organs including kidney, intestine, and bone. Alterations of mineral homeostasis are found in chronic kidney disease and other systemic disorders. The interplay between the immune system and the skeletal system is not fully understood, but cytokines play a major role in modulating calcitriol production and function. One of the main cellular signaling pathways mediating cytokine function is the Janus kinase (JAK)--signal transducer and activator of transcription (STAT) pathway. Here, we used a mouse model (Jak1^S645P+/- ) that resembles a constitutive activating mutation of the Jak1/Stat3 signaling pathway in humans, and shows altered mineral metabolism, with higher fibroblast growth factor 23 (FGF23) levels, lower PTH levels, and higher calcitriol levels. The higher calcitriol levels are probably due to extrarenal calcitriol production. Furthermore, systemic Jak1/Stat3 activation led to growth impairment and skeletal alterations. The growth plate in long bones showed decreased chondrocyte proliferation rates and reduced height of terminal chondrocytes. Furthermore, we demonstrate that Jak1 is also involved in bone remodeling early in life. Jak1^S645P+/- animals have decreased bone and cortical volume, imbalanced bone remodeling, reduced MAP kinase signaling, and local inflammation. In conclusion, Jak1 plays a major role in bone health probably both, directly and systemically by regulating mineral homeostasis. Understanding the role of this signaling pathway will contribute to a better knowledge in bone growth and in mineral physiology, and to the development of selective Jak inhibitors as osteoprotective agents.

Vitamin D receptor, vitamin D binding protein and CYP27B1 single nucleotide polymorphisms and susceptibility to viral infections in infants

The role of vitamin D in innate and adaptive immunity is recently under investigation. In this study we explored the potential association of genetic variances in vitamin D pathway and infections in infancy. Τhis prospective case–control study included infants 0–24 months with infection and age-matched controls. The single nucleotide polymorphisms of vitamin D receptor (VDR) gene (BsmI, FokI, ApaI, TaqI), vitamin D binding protein (VDBP) (Gc gene, rs7041, rs4588) and CYP27B1 (rs10877012) were genotyped by polymerase chain reaction-restriction fragment length polymorphism. In total 132 infants were enrolled, of whom 40 with bacterial and 52 with viral infection, and 40 healthy controls. As compared to controls, ΤaqI was more frequent in infants with viral infection compared to controls (p = 0.03, OR 1.96, 95% CI 1.1–3.58). Moreover, Gc1F was more frequent in the control group compared to infants with viral infection (p = 0.007, OR 2.7, 95% CI 1.3–5.6). No significant differences were found regarding the genetic profile for VDR and VDBP in infants with bacterial infection compared to the controls and also regarding CYP27B1 (rs10877012) between the studied groups. Genotypic differences suggest that vitamin D pathway might be associated with the host immune response against viral infections in infancy.

Comparative Biochemical Evaluation of the Proximate, Mineral, and Phytochemical Constituents of Xylopia aethiopica Whole Fruit, Seed, and Pericarp

This study evaluated the relative abundance of proximate, mineral, and phytochemical constituents of the anatomical parts of Xylopia aethiopica (XA) fruit using standard analytical procedures. The results showed that whole fruits (WF) have higher contents of crude protein, crude fiber, fat, ash, and moisture than the seeds (S) and pericarps (P). However, highest contents of crude carbohydrate and nitrogen free extracts were found in the P, followed by the S. The content of minerals (sodium, potassium, calcium, phosphorus, iron, zinc, magnesium, and copper) and phytochemicals were present in the following order of abundance: WF>S>P. Furthermore, the phytochemical constituents in each XA parts were present in the following order of relative abundance: total flavonoids>tannins>total phenolics>cardiac glycoside>alkaloids>steroids. Vitamin A was abundant in all three parts, with the abundance highest in WF [4.83±0.06 g vitamin A equivalent (vit A eq)/100 g] and lowest in P (1.64±0.02 g vit A eq/100 g). This preliminary study indicates XA fruits are rich in minerals, anti-nutrients, and phytochemicals. Therefore, these data could represent a biochemical rationale for inclusion of XA as a spice or functional ingredient in many Nigerian local soups to help prevent ailments.

Vitamin D and Vitamin D Analogs as Adjuncts to Field Therapy Treatments for Actinic Keratoses: Current Research and Future Approaches

Actinic keratoses (AK), also known as solar keratoses, are precancerous hyperkeratotic papules caused by long-term exposure to ultraviolet radiation. Management of AK prior to progression to cutaneous malignancy represents an important window of intervention. This is important on a population level, given the high incidence, morbidity, financial costs, and the low but measurable risk of mortality from cutaneous neoplasia. Treatments for AK have been refined for many years with significant progress over the past decade. Those recent advancements lead to questions about current treatment paradigms and the role of harnessing the immune system in field therapies. Recent studies suggest a key interplay between vitamin D and cancer immunity; in particular, the systemic and/or topical vitamin D analogs can augment field therapies used for severe actinic damage. In this review, we will examine the literature supporting the use of vitamin D-directed therapies to improve field therapy approaches. An enhanced understanding of these recent concepts with a focus on mechanisms is important in the optimized management of AK. These mechanisms will be critical in guiding whether selected populations, including those with immunosuppression, heritable cancer syndromes, and other risk factors for skin cancer, can benefit from these new concepts with vitamin D analogs and whether the approaches will be as effective in these populations as in immunocompetent patients.

Impact of Moriamin Forte on Testicular and Epididymal Damage in Rats with Oligoasthenospermia

To investigate the effect and mechanism of action of Moriamin Forte (MF) on oligoasthenospermia (OA) in rats exposed to multiglycosides of Tripterygium wilfordii (GTW), forty male Sprague Dawley rats were randomly divided into four groups. Rats in the control group were treated with 0.5% sodium carboxymethyl cellulose. The remaining rats were administered GTW (30 mg/kg/d) for 40 d to establish an OA model. Concurrently, the groups were treated with normal saline and low-dose (100 mg/kg/d) and high-dose (200 mg/kg/d) MF, respectively. After treatment, the number and motility of sperm cells were examined. Testicular and epididymal histomorphology changes were observed. Antioxidant indicators (SOD, CAT, MDA, TAC, and Nrf2) in testicular and epididymal tissues were detected. Apoptotic and antiapoptotic indicators (Bax and Bcl2 expression) in the testicular tissue were measured by immunohistochemistry. GTW decreased sperm count and motility, damaged testicular and epididymis tissues, impaired antioxidase activity, and increased tissue MDA levels. Meanwhile, GTW upregulated the expression of Bax and downregulated the expression of Bcl2. Western blot analysis demonstrated a decrease in the Nrf2 expression in the model group. Treatment with MF improved sperm count and motility, as well as inhibited the rate of apoptosis in the rat reproductive system. Moreover, MF improved the activity of antioxidants and increased the relative expression of the antioxidant pathway-related protein Nrf2. In conclusion, MF may reverse the GTW-induced OA by modulating the expression of apoptotic and antioxidant pathway-related proteins. This study may provide a pharmacological foundation for the use of MF in OA treatment.

Vitamin D Deficiency in Testicular Cancer Survivors: A Systematic Review

Testicular cancer (TC) is the most frequent tumor in young males. In the vast majority of cases, it is a curable disease; therefore, very often patients experience a long survival, also due to their young age at diagnosis. In the last decades, the role of the vitamin D deficiency related to orchiectomy has become an increasingly debated topic. Indeed, vitamin D is essential in bone metabolism and many other metabolic pathways, so its deficiency could lead to various metabolic disorders especially in long-term TC survivors. In our article, we report data from studies that evaluated the incidence of hypovitaminosis D in TC survivors compared with cohorts of healthy peers and we discuss molecular mechanisms and clinical implications.

Incidence rate of vitamin D deficiency and FGF23 levels in 12- to 13-year-old adolescents in Japan

INTRODUCTION

The incidence rate of vitamin D deficiency is increasing throughout the world. We measured the incidence rate of vitamin D deficiency and fibroblast growth factor 23 (FGF23) levels in 12- to 13-year-old adolescents in Japan.

MATERIALS AND METHODS

A total of 492 adolescents (247 boys and 245 girls) from Japanese community enrolled in this study. 25 hydroxyvitamin D (25(OH)D) was measured with radioimmunoassay. In the subjects with low 25(OH)D levels (≦ 20 ng/ml), intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), albumin (Alb), alkaline phosphatase (ALP) and FGF23 were measured.

RESULTS

25(OH)D levels were significantly lower in girls (20.9 ± 3.1 ng/ml) than in boys (22.2 ± 3.3 ng/ml) (p < 0.0001). Fifty-five boys (22.3%) and 83 (33.9%) girls showed vitamin D deficiency (< 20 ng/ml). One-hundred eighty-six (75.3%) boys and 162 (66.1%) girls showed vitamin D insufficiency (≧ 20 ng/ml, < 30 ng/ml). In the subjects whose 25(OH)D levels were ≦ 20 ng/ml, the levels of iPTH, Ca, P, Alb, ALP and FGF23 were 22.3 ± 9.0 pg/ml, 9.5 ± 0.4 mg/dl, 4.7 ± 0.6 mg/dl, 4.6 ± 0.3 g/dl, 920.8 ± 339.3 U/l and 42.6 ± 26.0 pg/ml, respectively. There was a significant negative association between serum 25(OH)D levels and iPTH [r =  - 0.290 (p < 0.0001)]. There was no significant association between serum 25(OH)D levels and FGF23.

CONCLUSION

We show that 28% of Japanese 12- to 13-year-old early adolescents suffer from vitamin D deficiency. Findings from this study indicate that vitamin D deficiency requires close oversight in public health during adolescence to ensure proper bone health.

Vitamin D and lumisterol derivatives can act on liver X receptors (LXRs)

The interactions of derivatives of lumisterol (L3) and vitamin D3 (D3) with liver X receptors (LXRs) were investigated. Molecular docking using crystal structures of the ligand binding domains (LBDs) of LXRα and β revealed high docking scores for L3 and D3 hydroxymetabolites, similar to those of the natural ligands, predicting good binding to the receptor. RNA sequencing of murine dermal fibroblasts stimulated with D3-hydroxyderivatives revealed LXR as the second nuclear receptor pathway for several D3-hydroxyderivatives, including 1,25(OH)2D3. This was validated by their induction of genes downstream of LXR. L3 and D3-derivatives activated an LXR-response element (LXRE)-driven reporter in CHO cells and human keratinocytes, and by enhanced expression of LXR target genes. L3 and D3 derivatives showed high affinity binding to the LBD of the LXRα and β in LanthaScreen TR-FRET LXRα and β coactivator assays. The majority of metabolites functioned as LXRα/β agonists; however, 1,20,25(OH)3D3, 1,25(OH)2D3, 1,20(OH)2D3 and 25(OH)D3 acted as inverse agonists of LXRα, but as agonists of LXRβ. Molecular dynamics simulations for the selected compounds, including 1,25(OH)2D3, 1,20(OH)2D3, 25(OH)D3, 20(OH)D3, 20(OH)L3 and 20,22(OH)2L3, showed different but overlapping interactions with LXRs. Identification of D3 and L3 derivatives as ligands for LXRs suggests a new mechanism of action for these compounds.

Recommendations on the measurement and the clinical use of vitamin D metabolites and vitamin D binding protein - A position paper from the IFCC Committee on bone metabolism

Vitamin D, an important hormone with a central role in calcium and phosphate homeostasis, is required for bone and muscle development as well as preservation of musculoskeletal function. The most abundant vitamin D metabolite is 25-hydroxyvitamin D [25(OH)D], which is currently considered the best marker to evaluate overall vitamin D status. 25(OH)D is therefore the most commonly measured metabolite in clinical practice. However, several other metabolites, although not broadly measured, are useful in certain clinical situations. Vitamin D and all its metabolites are circulating in blood bound to vitamin D binding protein, (VDBP). This highly polymorphic protein is not only the major transport protein which, along with albumin, binds over 99% of the circulating vitamin D metabolites, but also participates in the transport of the 25(OH)D into the cell via a megalin/cubilin complex. The accurate measurement of 25(OH)D has proved a difficult task. Although a reference method and standardization program are available for 25(OH)D, the other vitamin D metabolites still lack this. Interpretation of results, creation of clinical supplementation, and generation of therapeutic guidelines require not only accurate measurements of vitamin D metabolites, but also the accurate measurements of several other "molecules" related with bone metabolism. IFCC understood this priority and a committee has been established with the task to support and continue the standardization processes of vitamin D metabolites along with other bone-related biomarkers. In this review, we present the position of this IFCC Committee on Bone Metabolism on the latest developments concerning the measurement and standardization of vitamin D metabolites and its binding protein, as well as clinical indications for their measurement and interpretation of the results.

Multiplex LC-MS/MS for simultaneous determination of 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D3, albumin, and vitamin D-binding protein with its isoforms: One-step estimation of bioavailable vitamin D and vitamin D metabolite ratio

Bioavailable vitamin D and vitamin D metabolite ratio (VMR) have emerged as potential novel vitamin D markers. We developed a multiplex liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine all elements necessary for the calculation of bioavailable vitamin D and VMR, including 25-hydroxyvitamin D [25-(OH)D] and 24,25-dihydroxyvitamin D₃ [24,25-(OH)₂D₃], VDBP and its isoforms, and albumin. Following separate reactions of hexane extraction and trypsin digestion, serum samples were analyzed using LC-MS/MS to measure 25-(OH)D₃, 25-(OH)D₂, 24,25-(OH)₂D₃, VDBP and its isoforms, and albumin. Analytical performances were assessed. Korean (n = 229), Arab (n = 98), White (n = 99) and Black American (n = 99) samples were analyzed. Bioavailable vitamin D and VMR were calculated. All target molecules were clearly separated and accurately quantified by LC-MS/MS. Analytical performances, including imprecision, accuracy, ion suppression, limit of quantification, linearity, and comparison with existing methods were within acceptable levels. The allele frequencies of VDBP isoforms in various races resulted similar to previously known values. The levels of bioavailable vitamin D were highest in White Americans and lowest in Black Americans. We have successfully developed a multiplex LC-MS/MS-based assay method that can simultaneously perform the measurement of all parameters needed to calculate bioavailable vitamin D and VMR. Our devised method was robust and reliable in terms of analytical performances and could be applied to routine clinical samples in the future to more accurately assess vitamin D status.

Does vitamin D deficiency predispose to keloids via dysregulation of koebnerisin (S100A15)? A case-control study

Keloids result from uncontrolled inflammation and fibrosis during wound healing. Vitamin D can regulate skin proliferation and inflammation. Fibroblasts are vitamin D-responsive target cells and are source of koebnerisin (an antimicrobial peptide released during inflammation and wound healing). This study aimed to assess the levels and correlations between the serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin (S100A15) in patients with keloids. Nineteen patients with keloids and 20 matched controls were recruited. From each keloid patient, a serum sample and two biopsies were taken from the keloid (lesional) (Tissue A) and from normal skin (non-lesional) (Tissue B). From controls, a serum sample and a tissue biopsy from normal skin were taken. Serum and tissue 25-Hydroxyvitamin D, tissue vitamin D receptors, and serum and tissue koebnerisin were measured in retrieved samples using ELISA. Results revealed a significantly lower serum 25-Hydroxyvitamin D, tissue vitamin D receptors, as well as, serum and tissue koebnerisin in keloid patients compared to controls. Tissue 25-Hydroxyvitamin D was significantly lower in keloidal skin biopsy (Tissue A) compared to non-lesional normal skin biopsy (Tissue B). Tissue koebnerisin showed a significant positive correlation with tissue vitamin D receptors, and a significant negative correlation with tissue 25-Hydroxyvitamin D. There was a significant negative correlation between serum 25-Hydroxyvitamin D and duration of keloid. Accordingly, low serum and tissue 25-Hydroxyvitamin D and deficient tissue vitamin D receptors contribute to the pathogenesis of keloids. This can be partly mediated by dysregulation of the antimicrobial peptide; koebnerisin. Artificial antimicrobial peptides and koebnerisin-modifying drugs, for example, vitamin D and TNF-α inhibitors can have a role in keloid prevention and treatment.

Bone biomarkers in koalas: validation of assays and preliminary analyses

Traumatic injury, including bone fracture, is, to date, one of the leading causes of koala mortality in the South East Queensland region of Australia. Further, the specialist diet of koalas, which is restricted to certain Eucalyptus spp., may impact their normal bone physiology. Considering the dramatic koala population decline and high incidence of trauma, a greater understanding of koala bone physiology may support conservation. We retrieved from GenBank the protein sequences of parathyroid hormone (PTH), osteocalcin (OCN), and tissue-nonspecific alkaline phosphatase (TNALP) in human, dog, cattle, horse, koala, and gray short-tailed opossum. After homology was determined, plasma samples from 13 koalas were analyzed with human PTH, OCN, and bone-specific ALP (BALP) assay kits. Although koala PTH exhibited relatively low sequence homology with placental mammals, high sequence homology between humans and koalas was observed for both OCN and TNALP, and successful cross-reactivity was achieved using human enzyme immunoassay kits for detection of OCN and BALP biomarkers in koala plasma. However, we identified no correlation between OCN and BALP concentrations of healthy and trauma-affected koalas (p = 0.66 and p = 0.79, respectively). Further analysis of OCN and BALP in healthy and diseased koalas will allow a better understanding of bone physiology in this unique marsupial.

A Basic Review of the Preliminary Evidence That COVID-19 Risk and Severity Is Increased in Vitamin D Deficiency

As the world's attention has been riveted upon the growing COVID-19 pandemic, many researchers have written brief reports supporting the hypothesis that vitamin D deficiency is related to the incidence and severity of COVID-19. The clear common thread among the top risk groups-vitamin D deficiency-may be being overlooked because of previous overstated claims of vitamin D benefits. However, the need to decrease COVID-19 fatalities among high-risk populations is urgent. Early researchers reported three striking patterns. Firstly, the innate immune system is impaired by vitamin D deficiency, which would predispose sufferers to viral infections such as COVID-19. Vitamin D deficiency also increases the activity of the X-chromosome-linked "Renin-Angiotensin" System, making vitamin D deficient individuals (especially men) more susceptible to COVID-19's deadly "cytokine storm" (dramatic immune system overreaction). Secondly, the groups who are at highest risk for severe COVID-19 match those who are at highest risk for severe vitamin D deficiency. This includes the elderly, men, ethnic groups whose skin is naturally rich in melanin (if living outside the tropics), those who avoid sun exposure for cultural and health reasons, those who live in institutions, the obese, and/or those who suffer with hypertension, cardiovascular disease, or diabetes. And thirdly, the pattern of geographical spread of COVID-19 reflects higher population vitamin D deficiency. Both within the USA and throughout the world, COVID-19 fatality rates parallel vitamin D deficiency rates. A literature search was performed on PubMed, Google Scholar, and RSMLDS, with targeted Google searches providing additional sources. Although randomized controlled trial results may be available eventually, the correlational and causal study evidence supporting a link between vitamin D deficiency and COVID-19 risks is already so strong that it supports action. The 141 author groups writing primarily about biological plausibility detailed how vitamin D deficiency can explain every risk factor and every complication of COVID-19, but agreed that other factors are undoubtedly at work. COVID-19 was compared with dengue fever, for which oral vitamin D supplements of 4,000 IU for 10 days were significantly more effective than 1,000 IU in reducing virus replication and controlling the "cytokine storm" (dramatic immune system over-reaction) responsible for fatalities. Among the 47 original research studies summarized here, chart reviews found that serum vitamin D levels predicted COVID-19 mortality rates (16 studies) and linearly predicted COVID-19 illness severity (8 studies). Two causal modeling studies and several analyses of variance strongly supported the hypothesis that vitamin D deficiency is a causal, rather than a bystander, factor in COVID-19 outcomes. Three of the four studies whose findings opposed the hypothesis relied upon disproven assumptions. The literature review also found that prophylactically correcting possible vitamin D deficiency during the COVID-19 pandemic is extremely safe. Widely recommending 2,000 IU of vitamin D daily for all populations with limited ability to manufacture vitamin D from the sun has virtually no potential for harm and is reasonably likely to save many lives.

Vitamin D Megadose: Definition, Efficacy in Bone Metabolism, Risk of Falls and Fractures

Introduction

Currently, approximately more than one billion people around the world are considered to have deficient levels of vitamin D. International consensus recommends vitamin D supplementation to high-risk patients (advanced age, osteoporosis, liver failure, malabsorption syndromes, etc.) and those with levels below 30 ng/mL. There are several vitamin D formulations and dosages available, including megadoses. At the moment, there is no consensus on the definition of megadoses. The purpose of this review is to define what is a megadose and analyze its effectiveness in bone metabolism, risk of fractures and falls.

Conclusion

The administration of doses higher than 100,000 IU of vitamin D is considered a megadose. It is evident that the use of megadoses increases serum concentrations of vitamin D; however, there has been no evidence of a decrease in the risk of falls, vertebral fractures or changes in bone mineral density.

Detection of 7-Dehydrocholesterol and Vitamin D3 Derivatives in Honey

20(S)-Hydroxyvitamin D3 (20(OH)D3) is an endogenous metabolite produced by the action of CYP11A1 on the side chain of vitamin D3 (D3). 20(OH)D3 can be further hydroxylated by CYP11A1, CYP27A1, CYP24A1 and/or CYP27B1 to several hydroxyderivatives. CYP11A1 also hydroxylates D3 to 22-monohydroxyvitamin D3 (22(OH)D3), which is detectable in the epidermis. 20-Hydroxy-7-dehydrocholesterol (20(OH)-7DHC) has been detected in the human epidermis and can be phototransformed into 20(OH)D3 following the absorption of ultraviolet B (UVB) energy by the B-ring. 20(OH)D3 and its hydroxyderivatives have anti-inflammatory, pro-differentiation and anti-proliferative effects, comparable to 1,25-dihydroxyvitamin D3 (1,25(OH)₂D3). Since cytochromes P450 with 20- or 25-hydroxylase activity are found in insects participating in ecdysone synthesis from 7-dehydrocholesterol (7DHC), we tested whether D3-hydroxyderivatives are present in honey, implying their production in bees. Honey was collected during summer in the Birmingham area of Alabama or purchased commercially and extracted and analyzed using LC-MS. We detected a clear peak of m/z = 423.324 [M + Na]⁺ for 20(OH)D3 corresponding to a concentration in honey of 256 ng/g. We also detected peaks of m/z = 383.331 [M + H − H₂O]⁺ for 20(OH)-7DHC and 25(OH)D3 with retention times corresponding to the standards. We further detected species with m/z = 407.329 [M + Na]⁺ corresponding to the RT of 7DHC, D3 and lumisterol3 (L3). Similarly, peaks with m/z = 399.326 [M + H − H₂O]⁺ were detected at the RT of 1,25(OH)₂D3 and 1,20-dihydroxyvitamin D3 (1,20(OH)₂D3). Species corresponding to 20-monohydroxylumisterol3 (20(OH)L3), 22-monohydroxyvitamin D3 (22(OH)D3), 20,23-dihydroxyvitamin D3 (20,23(OH)₂D3), 20,24/25/26-dihydroxyvitamin D3 (20,24/25/26(OH)₂D3) and 1,20,23/24/25/26-trihydroxyvitamin D3 (1,20,23/24/25/26(OH)₃D3) were not detectable above the background. In conclusion, the presence of 7DHC and D3 and of species corresponding to 20(OH)-7DHC, 20(OH)D3, 1,20(OH)₂D3, 25(OH)D3 and 1,25(OH)₂D3 in honey implies their production in bees, although the precise biochemistry and photochemistry of these processes remain to be defined.

Efficacy of Vitamin D3 Buccal Spray Supplementation Compared to Other Delivery Methods: A Systematic Review of Superiority Randomized Controlled Trials

(1) Background: Vitamin D deficiency is an important public health concern and supplementation is common for this deficiency. Many different modes of delivering supplementation have been proposed in order to enhance absorption and utilization. The present review compared the efficacy of vitamin D₃ buccal spray against other forms of supplementation delivery. (2) Methods: The protocol was registered at PROSPERO (CRD42019136146). Medline/PubMed, CENTRAL and clinicaltrials.gov were searched from their inception until September 2019, for randomized controlled trials (RCTs) that compare vitamin D₃ delivery via sublingual spray against other delivery methods. Eligible RCTs involved humans, of any age and health status, published in any language that evaluated changes in plasma 25(OH)D concentrations. Three reviewers independently extracted data, assessed risk of bias (RoB) and the quality of the trials. (3) Results: Out of 9759 RCTs, four matched the predefined criteria. Intervention duration ranged from 30 days to 3 months whereas vitamin D₃ dosage ranged between 800 and 3000 IU/day. One RCT advocated for the superiority of buccal spray in increasing plasma 25(OH)D concentrations, although several limitations were recorded in that trial. The rest failed to report differences in post-intervention 25(OH)D concentrations between delivery methods. Considerable clinical heterogeneity was observed due to study design, intervention duration and dosage, assays and labs used to perform the assays, population age and health status, not allowing for synthesis of the results. (4) Conclusions: Based on the available evidence, delivery of vitamin D₃ via buccal spray does not appear superior to the other modes of delivery. Future RCTs avoiding the existing methodological shortcomings are warranted.

Free vitamin D levels in steroid-sensitive nephrotic syndrome and healthy controls

INTRODUCTION

Body stores of vitamin D are measured as "total" serum 25-hydroxy vitamin D (25(OH)D). Its largest component is protein bound and lost in urine in nephrotic syndrome (NS). Our study investigates whether "free" 25(OH)D levels are a better guide to bone health and need for vitamin D supplementation in patients with steroid-sensitive NS (SSNS).

METHODS

A cross-sectional study was performed in children with SSNS and healthy controls. Blood was tested for albumin, creatinine, calcium, phosphate, ALP, total and free (by direct ELISA) 25(OH)D, iPTH, and urine for protein-creatinine ratio.

RESULTS

Seventy-nine NS patients (48 in relapse, 31 in remission) and 60 healthy controls were included. The levels of total 25(OH)D were significantly different (lowest in NS relapse and highest in controls) (p < 0.001). Corrected calcium and phosphate levels were normal, and there were no differences in free 25(OH)D, ALP, or iPTH levels between groups. Only total and not free 25(OH)D correlated significantly and negatively with urinary protein creatinine ratios (r_s = - 0.42 vs. 0.04). Free 25(OH)D values of 3.75 and 2.85 pg/ml corresponded to total 25(OH)D levels of 20 and 12 ng/ml, respectively, in healthy controls.

CONCLUSION

These results confirm that total 25(OH)D levels are low in NS and related to degree of proteinuria. However levels of free 25(OH)D, ALP, and iPTH did not change in relapse or remission in comparison with healthy controls. Our results suggest that in proteinuric renal diseases, free 25(OH)D rather than total 25(OH)D levels should be used to diagnose vitamin D deficiency and guide therapy.