Vitamin D deficiency: the time to ignore it has passed

Independent and interactive associations of season, dietary vitamin D, and vitamin D-related genetic variants with serum 25(OH)D in Korean adults aged 40 years or older

Only limited information is available on the inter-relationships between genetic and non-genetic factors such as diet and sunlight exposure with serum 25-hydroxyvitamin D [25(OH)D] concentration. This cross-sectional study aimed to examine the independent and interactive associations of season, dietary vitamin D intake, and SNPs of 11 vitamin D-related candidate genes with serum 25(OH)D concentration among 2,721 adults aged ≥40 years at baseline from the Yangpyeong cohort, a part of the Korean Genome Epidemiology Study (KoGES). The interactions between season or dietary vitamin D and 556 SNPs were evaluated using 2-degree of freedom joint tests. Season was strongly (p_difference = 1.00 × 10^-12) and dietary vitamin D intake was slightly but significantly associated with serum 25(OH)D concentration (p_difference = 0.0119). Among five SNPs (rs11723621-GC, rs7041-GC, rs10500804-CYP2R1, rs7129781-CYP2R1, and rs2852853-DHCR7) identified in the screening steps, only one, rs10500804-CYP2R1, significantly interacted with season (p_interaction = 8.01 × 10^-5). The inverse association between number of minor alleles of rs10500804-CYP2R1 and concentration of 25(OH)D was significant only in summer/fall. Conversely, dietary vitamin D intake was positively associated only in winter/spring. In conclusion, season, dietary vitamin D intake, and four SNPs in GC, CYP2R1, and DHCR7 are independently and rs10500804-CYP2R1 is interactively associated with serum 25(OH)D concentration. Serum 25(OH)D is influenced by genotype of rs10500804-CYP2R1 in summer/fall when sunlight exposure is high, while dietary vitamin D intake is an important determinant of serum 25(OH)D during the seasons with low cutaneous vitamin D synthesis.

Serum 25-Hydroxyvitamin D and Intact Parathyroid Hormone Influence Muscle Outcomes in Children and Adolescents

Increases in 25-hydroxyvitamin D concentrations are shown to improve strength in adults; however, data in pediatric populations are scant and equivocal. In this ancillary study of a larger-scale, multi-sited, double-blind, randomized, placebo-controlled vitamin D intervention in US children and adolescents, we examined the associations between changes in vitamin D metabolites and changes in muscle mass, strength, and composition after 12 weeks of vitamin D3 supplementation. Healthy male and female, black and white children and adolescents between the ages of 9 and 13 years from two US states (Georgia 34°N and Indiana 40°N) were enrolled in the study and randomly assigned to receive an oral vitamin D3 dose of 0, 400, 1000, 2000, or 4000 IU/d for 12 weeks between the winter months of 2009 to 2011 (N = 324). Analyses of covariance, partial correlations, and regression analyses of baseline and 12-week changes (post-baseline) in vitamin D metabolites (serum 25(OH)D, 1,25(OH)2 D, intact parathyroid hormone [iPTH]), and outcomes of muscle mass, strength, and composition (total body fat-free soft tissue [FFST], handgrip strength, forearm and calf muscle cross-sectional area [MCSA], muscle density, and intermuscular adipose tissue [IMAT]) were assessed. Serum 25(OH)D and 1,25(OH)2 D, but not iPTH, increased over time, as did fat mass, FFST, forearm and calf MCSA, forearm IMAT, and handgrip strength (p < 0.05). Vitamin D metabolites were not associated with muscle strength at baseline nor after the 12-week intervention. Changes in serum 25(OH)D correlated with decreases in forearm IMAT, whereas changes in serum iPTH predicted increases in forearm and calf MCSA and IMAT (p < 0.05). Overall, increases in 25(OH)D did not influence muscle mass or strength in vitamin D-sufficient children and adolescents; however, the role of iPTH on muscle composition in this population is unknown and warrants further investigation. © 2018 American Society for Bone and Mineral Research.

Prevalence of vitamin D deficiency in healthy Iranian children: A systematic review and meta-analysis

Background: Vitamin D deficiency is related to rickets in children, and it can increase the risk of osteoporosis in adulthood. The aim of our study was to estimate the prevalence of vitamin D deficiency among healthy Iranian children and adolescents. Vitamin D levels less than 20ng/ml and between 20 and 30ng/ml was considered as vitamin D deficiency and insufficiency, respectively. Methods: Relevant observational studies evaluating the prevalence of vitamin D deficiency through 1 January 1990 to 28 Dec 2016, were searched in several electronic databases including Iran-Medex, Scientific Information Database (SID), Irandoc, PubMed and NLM Gateway (for MEDLINE), Web of Science, and Scopus with no restriction on language. Only full-text articles were used for data extraction and synthesis after considering the inclusion/exclusion criteria. Results: 11 studies included; the data of four studies of Iranian newborns were withdrawn because of their high heterogeneity. The prevalence of vitamin D deficiency in Iranian boys and girls were 35% (CI 95% 34-37) and 61% (CI 95% 60-63), respectively. The prevalence of vitamin D insufficiency in Iranian children and adolescents was 31% (CI 95% 30-31). Conclusion: It seems that the prevalence of vitamin D deficiency is very high among Iranian children and adolescents. The present findings could provide practical information for healthcare decision makers.

Is there any correlation between vitamin D insufficiency and diabetic retinopathy?

AIM

To determine a relation between vitamin D level, which is an inhibitor of angiogenesis, and diabetic retinopathy and its risk factors.

METHODS

In a clinic-based cross sectional study two hundred and thirty-five type 2 diabetic patients older than 20y were selected. Patients were classified according to ophthalmologic examination as following: no diabetic retinopathy (NDR) (n=153), non-proliferative diabetic retinopathy (NPDR) (n=64) and proliferative diabetic retinopathy (PDR) (n=18). Study subjects were tested for fasting blood glucose, glycated hemoglobin A1C (HbA1C), lipid profile, microalbuminuria, HsCRP, IGF1, insulin (in patients without history of insulin taking) and 25 hydroxy vitamin D [25 (OH) D] levels. Vitamin D insufficiency was defined according to 25 (OH) D level less than 30 ng/mL. The relationship between diabetic retinopathy and serum 25 (OH) D insufficiency was evaluated.

RESULTS

The prevalence of diabetic retinopathy was 34.8% in our patients. Long duration of diabetes, hypertension, poor glycemic control, diabetic nephropathy, hyperinsulinemia and insulin resistance were risk factors for diabetic retinopathy but 25 (OH) D level was not significant different between NDR, NPDR and PDR groups. Correlation between 25 (OH) D level and other known risk factors of diabetic retinopathy was not significant.

CONCLUSION

This study did not find any association between diabetic retinopathy and its severity and vitamin D insufficiency. Vitamin D insufficiency is not related to risk factors of diabetic retinopathy.

Effects of vitamin D on patients with fibromyalgia syndrome: a randomized placebo-controlled trial

The role of calcifediol in the perception of chronic pain is a widely discussed subject. Low serum levels of calcifediol are especially common in patients with severe pain and fibromyalgia syndrome (FMS). We lack evidence of the role of vitamin D supplementation in these patients. To our knowledge, no randomized controlled trial has been published on the subject. Thirty women with FMS according to the 1990 and 2010 American College of Rheumatology criteria, with serum calcifediol levels <32ng/mL (80nmol/L), were randomized to treatment group (TG) or control group (CG). The goal was to achieve serum calcifediol levels between 32 and 48ng/mL for 20weeks via oral supplementation with cholecalciferol. The CG received placebo medication. Re-evaluation was performed in both groups after a further 24weeks without cholecalciferol supplementation. The main hypothesis was that high levels of serum calcifediol should result in a reduction of pain (visual analog scale score). Additional variables were evaluated using the Short Form Health Survey 36, the Hospital Anxiety and Depression Scale, the Fibromyalgia Impact Questionnaire, and the Somatization subscale of Symptom Checklist-90-Revised. A marked reduction in pain was noted over the treatment period in TG: a 2 (groups)×4 (time points) variance analysis showed a significant group effect in visual analog scale scores. This also was correlated with scores on the physical role functioning scale of the Short Form Health Survey 36. Optimization of calcifediol levels in FMS had a positive effect on the perception of pain. This economical therapy with a low side effect profile may well be considered in patients with FMS. However, further studies with larger patient numbers are needed to prove the hypothesis.

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168 000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2 nmol/l), with 37·3 % of the studies reporting mean values below 50 nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D status.

[Depressive symptoms and widespread pains in a prisoner: think on vitamin D deficiency]

The confinement can lead to an important limitation of sun exposure of the prisoners. This limitation can lead to a deficit in vitamin D, source of diverse disorders. Diffuse pains of members and of joints are the most classics troubles. The association of vitamin D deficiency and psychiatric disorders is frequent but badly known. Even if there is still no evidence indicating a cause and effect relationship between vitamin D deficiency and depressive episodes, the contribution of vitamin D deficiency in the arisen of a depression has to be considered. The treatment of vitamin D deficiency cannot, in itself, constitute a treatment of the depressive disorder but contributes to the improvement of the whole status The psychiatric follow-up remains indispensable, in particular because of the suicidal risk, particularly present in prison.

Vitamin D and multiple sclerosis: a critical review and recommendations on treatment

Multiple sclerosis (MS) is an immune-mediated and degenerative disease of nervous system, which affects mostly young adults. Vitamin D deficiency is a well-known environmental risk factor for MS and is considerable in terms of immediate clinical implications. In addition to its classical action on regulation of bone homeostasis, vitamin D may have a potent impact on cytokine profiles and neuro-inflammation. Given the immunomodulatory effects of vitamin D and its high rate of deficiency in MS patients, prescribing vitamin D is a remarkable issue in MS. The results from several experimental and clinical studies indicate that vitamin D supplementation may ameliorate the inflammation during the relapse phase and attenuate disease progression. We present the experimental and clinical studies, which assessed the effects of vitamin D on the pathophysiology, prevalence and management of MS. The authors also discuss current recommendations on prescription of this vitamin to MS patients.

Vitamin D levels: its relationship to bone mineral density response and disease activity in premenopausal Malaysian systemic lupus erythematosus patients on corticosteroids

AIM

To determine if baseline vitamin D levels would influence the gain in bone mineral density (BMD) in female systemic lupus erythematosus (SLE) patients on corticosteroids (CS) taking bone-active medication.

METHOD

Premenopausal SLE patients participating in a trial assessing the efficacy of calcium alone, calcitriol and calcium, and alendronate and calcium, on BMD in patients on CS, were studied. Patients were randomly allocated to the treatment groups at the start of the study and followed up for 2 years. Serum 25-hydroxy vitamin D [25(OH)D] was measured at baseline.

RESULTS

  Thirty-eight patients were studied. One (2%) patient had osteoporosis, nine (24%) had osteopenia and all others had normal BMD. The mean baseline 25(OH)D levels were 21.6 ± 4.6 ng/mL (± 1 SD). Twelve (32%) patients had vitamin D deficiency [25(OH)D < 20 ng/mL]. There was a significant negative correlation between SLEDAI scores and 25(OH)D levels, that is, patients with high SLEDAI scores had significantly lower 25(OH)D levels (P = 0.033). Left femoral neck BMD was significantly lower in the deficient compared to insufficient group (P = 0.042). There was a trend toward better BMD gain at 2 years in the vitamin D insufficient compared to the deficient group, which did not reach statistical significance.

CONCLUSION

This study showed that in female SLE patients, low vitamin D levels are associated with higher disease activity and suggests that patients who have higher vitamin D levels have a better BMD response during treatment with bone-active agents.

Widespread vitamin D insufficiency: A new challenge for primary prevention, with particular reference to multiple sclerosis

In the past 10 years, our knowledge of vitamin D has been revolutionized on two main points. Firstly, this vitamin is not only crucial for bone and calcium metabolism but also exerts major hormonal actions via its active metabolite (calcitriol) and specific receptors in almost all organs. The diverse non-classical actions of vitamin D-i.e. anti-inflammatory, immunomodulatory, antiproliferative and as a neurotransmitter-could have protective and preventive effects for a wide variety of pathologies, such as autoimmune diseases, cancer, infections and cardiovascular affections. Secondly, daily vitamin D requirements have been redefined thanks to many recent metabolic and pathological studies and are about 10 times higher than the amount considered sufficient until a few years ago. The fact that sunshine is the essential natural source of vitamin D and is limited in temperate and Nordic countries, coupled with the fact that modern lifestyle increasingly removes people from exposure to the sun, could explain why a great majority of the general population in these countries are in a state of vitamin D insufficiency. A lack of vitamin D can therefore also be observed in all pathologies but it may play a pathogenic role only in some of them. The incrimination of hypovitaminosis D as a risk factor is a reasonable assumption when several different research approaches used in a given pathology have consistently concluded that vitamin D is likely involved in that pathology. In multiple sclerosis, taken here as a prime example, there is a substantial rationale for vitamin D involvement, based on the findings of different experimental, epidemiological, genetic and immunological studies. Possible curative effects of vitamin D, in addition to a preventive action, are currently being tested but have not yet been demonstrated in most pathologies. However, these two questions appear to be clearly distinct and may involve notably different mechanisms. Lastly, since vitamin D insufficiency exists in most people living in mid- or high-latitude countries, vitamin D could exert multiple major preventive actions, simple supplementation is both safe and inexpensive and, for a vitamin-hormone, supplementation seems obligatory from a general preventive medical point of view alone, it follows that vitamin D supplementation should be organized in these countries to treat all those currently in a state of insufficiency, patients and 'normal' subjects alike, without further delay.