Vitamin D and the intestinal absorption of iron and cobalt

Low vitamin D status is associated with anaemia in hospitalised cats

BACKGROUND

The major physiological role of vitamin D has traditionally been considered to be the regulation of calcium homeostasis and maintenance of skeletal health. However, there is increasing evidence that vitamin D influences a wider range of physiological processes including erythropoiesis. Vitamin D (25-hydroxyvitamin D, 25(OH)D) deficiency concentrations have been associated with anaemia in human beings. In contrast, the relationship between vitamin D status and erythropoiesis has not been investigated in cats.

METHODS

Clinical records of cats consecutively presenting between November 2013 and February 2015 were reviewed. For each cat, data including sex, age, breed, serum albumin and creatinine concentrations, and appetite scores were extracted. A multivariable linear regression model was constructed to examine the relationship between 25(OH)D concentrations and these variables.

RESULTS

Cats with anaemia had significantly lower 25(OH)D concentrations (median 49.5 nmol/l, n=31) than cats with packed cell volume above the lower limit of the reference range (median 109.0 nmol/l, n=130) (P<0.001). A binary logistic regression found that red blood cell count and mean corpuscular volume were negatively correlated with serum 25(OH)D concentrations (P<0.001 and P=0.007, respectively).

CONCLUSION

Vitamin D (25(OH)D) concentration is positively associated with red blood cell count and mean corpuscular volume in cats with a wide range of different illnesses.

Vitamin D Treatment during Pregnancy and Maternal and Neonatal Cord Blood Metal Concentrations at Delivery: Results of a Randomized Controlled Trial in Bangladesh

BACKGROUND

Vitamin D improves absorption of calcium; however, in animal studies vitamin D also increases the absorption of toxic metals, such as lead and cadmium.

OBJECTIVES

We examined maternal and neonatal cord blood levels of lead, cadmium, manganese, and mercury after supplementation with vitamin D during pregnancy.

METHODS

The Maternal Vitamin D for Infant Growth trial was a randomized, placebo-controlled, multi-arm study of maternal vitamin D supplementation during pregnancy in Dhaka, Bangladesh (NCT01924013). Women were randomized during their second trimester to blinded weekly doses of placebo or 4,200, 16,800, or 28,000 IU of vitamin D3 throughout pregnancy. Each group had 118-239 maternal blood specimens and 100-201 cord blood samples analyzed. Metals were measured using inductively coupled plasma mass spectrometry. Unadjusted estimates from linear regression models were expressed as percentage differences. Cord blood cadmium was analyzed as detectable or undetectable with log-binomial regression.

RESULTS

Maternal cadmium, mercury, and manganese levels were nearly identical across groups. Maternal lead levels were 6.3%, 7.4%, and 6.0% higher in the treatment groups (4,200, 16,800, and 28,000 IU, respectively) vs. placebo; however, 95% confidence intervals (CIs) showed that differences from 4.1% lower to 20% higher were compatible with the data. In treatment groups (4,200, 16,800, 28,000 IU) vs. placebo, neonatal cord blood lead levels were 8.5% (95% CI: - 3.5 , 22), 16% (95% CI: 3.3, 30), and 11% (95% CI: 0.4, 23) higher and had higher risk of detectable cadmium, relative risk ( RR ) = 2.2 (95% CI: 1.3, 3.7), RR = 1.4 (95% CI: 0.8, 2.5), RR = 1.7 (95% CI: 1.0, 2.9).

DISCUSSION

Vitamin D supplementation from the second trimester of pregnancy did not influence maternal cadmium, mercury, or manganese levels at delivery. Vitamin D was associated with nonsignificant increases in maternal lead and with significant increases in cord blood lead and cadmium. These associations were not dose dependent. Given that there are no safe levels of metals in infants, the observed increases in cord blood lead and cadmium require further exploration. https://doi.org/10.1289/EHP7265.

Computational model for vitamin D deficiency using hair mineral analysis

Vitamin D deficiency is prevalent in the Arabian Gulf region, especially among women. Recent studies show that the vitamin D deficiency is associated with a mineral status of a patient. Therefore, it is important to assess the mineral status of the patient to reveal the hidden mineral imbalance associated with vitamin D deficiency. A well-known test such as the red blood cells is fairly expensive, invasive, and less informative. On the other hand, a hair mineral analysis can be considered an accurate, excellent, highly informative tool to measure mineral imbalance associated with vitamin D deficiency. In this study, 118 apparently healthy Kuwaiti women were assessed for their mineral levels and vitamin D status by a hair mineral analysis (HMA). This information was used to build a computerized model that would predict vitamin D deficiency based on its association with the levels and ratios of minerals. The first phase of the proposed model introduces a novel hybrid optimization algorithm, which can be considered as an improvement of Bat Algorithm (BA) to select the most discriminative features. The improvement includes using the mutation process of Genetic Algorithm (GA) to update the positions of bats with the aim of speeding up convergence; thus, making the algorithm more feasible for wider ranges of real-world applications. Due to the imbalanced class distribution in our dataset, in the second phase, different sampling methods such as Random Under-Sampling, Random Over-Sampling, and Synthetic Minority Oversampling Technique are used to solve the problem of imbalanced datasets. In the third phase, an AdaBoost ensemble classifier is used to predicting the vitamin D deficiency. The results showed that the proposed model achieved good results to detect the deficiency in vitamin D.

Independent associations of vitamin D metabolites with anemia in patients referred to coronary angiography: the LURIC study

PURPOSE

Anemia and vitamin D deficiency are both frequent in adult patients. Whether low vitamin D metabolite levels are an independent risk factor for different subtypes of anemia remains to be studied in detail.

METHODS

In 3299 patients referred for coronary angiography, we investigated the association of 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25(OH)₂D] with anemia [hemoglobin (Hb) <12.5 g/dl] of specific subtypes.

RESULTS

Compared with patients with 25OHD levels in the adequate range (50-125 nmol/l), patients with deficient 25OHD concentrations (<30 nmol/l; 33.6 % of patients) had 0.6 g/dl lower Hb levels. Hb values were 1.3 g/dl lower in patients with 1,25(OH)₂D levels <40 pmol/l (5.4 % of patients), compared with patients in the highest 1,25(OH)₂D category (>70 pmol/l). Of the participants, 16.7 % met the criteria for anemia. In multivariate-adjusted regression analyses, the odds ratios for anemia in the lowest 25OHD and 1,25(OH)₂D categories were 1.52 (95 % CI 1.15-2.02) and 3.59 (95 % CI 2.33-5.52), compared with patients with 25OHD levels in the adequate range and patients with 1,25(OH)₂D levels >70 pmol/l. The probability of anemia was highest in patients with combined 25OHD and 1,25(OH)₂D deficiency [multivariable-adjusted odds ratio 5.11 (95 % CI 2.66-9.81)]. Patients with anemia of chronic kidney disease had the highest prevalence of 25OHD deficiency and 1,25(OH)₂D concentrations of <40 pmol/l.

CONCLUSIONS

Low 25OHD and 1,25(OH)₂D concentrations are independently associated with anemia. Patients with poor kidney function are most affected. Interventional trials are warranted to prove whether administration of plain or activated vitamin D can prevent anemia.

An evaluation of sleep quality and the prevalence of restless leg syndrome in vitamin D deficiency

Vitamin D is known to increase levels of dopamine and its metabolites in the brain and also protects dopaminergic neurons against dopaminergic toxins. The aims of the study were to assess the frequency and symptom severity of restless leg syndrome (RLS) and sleep quality in vitamin D deficiency. A total of 102 patients were enrolled in this cross-sectional study, comprising 57 vitamin D deficient patients as Group 1 and 45 patients with normal levels of vitamin D as Group 2. RLS was diagnosed according to the International RLS Study Group (IRLSSG) diagnostic criteria. Symptom severity was assessed using the IRLSSG rating scale and sleep quality was measured with the Pittsburgh sleep quality index (PSQI). RLS incidence was higher in Group 1 (p = 0.034). The PSQI scores were higher in Group 1 and the difference between the groups was determined as statistically significant (p < 0.05). No statistically significant difference was determined in respect of the clinical evaluation and the IRLSSG Symptom Severity Scale between the patients in Group 1 diagnosed with RLS and the patients in Group 2 diagnosed with RLS (p > 0.05). The findings of this study support the hypothesis that RLS is more frequent and more severe in vitamin D deficiency and indicate a negative effect of vitamin deficiency on sleep parameters.

Vitamin D, Essential Minerals, and Toxic Elements: Exploring Interactions between Nutrients and Toxicants in Clinical Medicine

In clinical medicine, increasing attention is being directed towards the important areas of nutritional biochemistry and toxicant bioaccumulation as they relate to human health and chronic disease. Optimal nutritional status, including healthy levels of vitamin D and essential minerals, is requisite for proper physiological function; conversely, accrual of toxic elements has the potential to impair normal physiology. It is evident that vitamin D intake can facilitate the absorption and assimilation of essential inorganic elements (such as calcium, magnesium, copper, zinc, iron, and selenium) but also the uptake of toxic elements (such as lead, arsenic, aluminum, cobalt, and strontium). Furthermore, sufficiency of essential minerals appears to resist the uptake of toxic metals. This paper explores the literature to determine a suitable clinical approach with regard to vitamin D and essential mineral intake to achieve optimal biological function and to avoid harm in order to prevent and overcome illness. It appears preferable to secure essential mineral status in conjunction with adequate vitamin D, as intake of vitamin D in the absence of mineral sufficiency may result in facilitation of toxic element absorption with potential adverse clinical outcomes.

Independent association of circulating vitamin D metabolites with anemia risk in patients scheduled for cardiac surgery

BACKGROUND

Preoperative anemia is considered an independent risk factor of poor clinical outcome in cardiac surgical patients. Low vitamin D status may increase anemia risk.

METHODS

We investigated 3,615 consecutive patients scheduled for cardiac surgery to determine the association between preoperative anemia (hemoglobin [Hb] <12.5 g/dL) and circulating levels of the vitamin D metabolites 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25[OH]2D).

RESULTS

Of the study cohort, 27.8 % met the criteria for anemia. In patients with deficient 25OHD levels (<30 nmol/l) mean Hb concentrations were 0.5 g/dL lower than in patients with adequate 25OHD levels (50.0-125 nmol/l; P<0.001). Regarding 1,25(OH)2D, mean Hb concentrations were 1.2 g/dL lower in the lowest 1,25(OH)2D category (<40 pmol/l) than in the highest 1,25(OH)2D category (>70 pmol/l; P<0.001). In multivariable-adjusted logistic regression analyses, the odds ratios for anemia of the lowest categories of 25OHD and 1,25(OH)2D were 1.48 (95%CI:1.19-1.83) and 2.35 (95%CI:1.86-2.97), compared with patients who had adequate 25OHD levels and 1,25(OH)2D values in the highest category, respectively. Anemia risk was greatest in patients with dual deficiency of 25OHD and 1,25(OH)2D (multivariable-adjusted OR = 3.60 (95%CI:2.40-5.40). Prevalence of deficient 25OHD levels was highest in anemia of nutrient deficiency, whereas low 1,25(OH)2D levels were most frequent in anemia of chronic kidney disease.

CONCLUSION

This cross-sectional study demonstrates an independent inverse association between vitamin D status and anemia risk. If confirmed in clinical trials, preoperative administration of vitamin D or activated vitamin D (in case of chronic kidney disease) would be a promising strategy to prevent anemia in patients scheduled for cardiac surgery.

Proteomic analysis of the cerebrospinal fluid of patients with restless legs syndrome/Willis-Ekbom disease

BACKGROUND

Restless Legs Syndrome/Willis-Ekbom Disease (RLS/WED) is a sensorimotor disorder that causes patients to experience overwhelming and distressing sensations in the legs compelling the patient to move their legs to provide relief. The purpose of this study was to determine if biomarkers in the cerebrospinal fluid can distinguish RLS/WED patients from neurological controls.

METHODS

We obtained CSF samples by lumbar puncture from 5 early-onset RLS/WED patients and 5 controls. We performed 2-dimensional difference in-gel electrophoresis (2D-DIGE). Proteins that were significantly altered were identified by Student's t-test. Protein spots that were differentially expressed (p ≤ 0.05, Av. Ratio ≥ 2.0) between RLS/WED and control CSF samples were identified using MALDI-TOF-MS. Statistical analyses of the validation immunoblot assays were performed using Student's t-test.

RESULTS

In this discovery study we identified 6 candidate CSF protein markers for early-onset RLS/WED. Four proteins (Cystatin C, Lipocalin-type Prostaglandin D2 Synthase, Vitamin D binding Protein, and β-Hemoglobin) were increased and 2 proteins (Apolipoprotein A1 and α-1-acid Glycoprotein) were decreased in RLS/WED patients.

CONCLUSIONS

Our results reveal a protein profile in the RLS/WED CSF that is consistent with clinical findings of disruptive sleep, cardiovascular dysfunction and painful symptoms. Moreover, protein profiles are consistent with neuropathological findings of activation of hypoxia inducible factor (HIF) pathways and alterations in dopaminergic systems. These data indicate the CSF of RLS/WED patients may provide information relevant to biological basis for RLS/WED, treatment strategies and potential new treatment targets.

Association of 25-hydroxyvitamin D with anemia risk in patients scheduled for cardiac surgery

INTRODUCTION

There is emerging data that vitamin D plays a role in erythropoiesis. Low 25-hydroxyvitamin D (25OHD) levels may therefore be a risk factor for anemia in patients scheduled for cardiac surgery.

METHODS

We investigated 4428 consecutive cardiac surgical patients to determine an association between anemia (hemoglobin concentration <12.5 g/dL, 27.1% of the study cohort) and circulating 25OHD.

RESULTS

In patients with severe vitamin D deficiency (25OHD < 12.5 nm), mean hemoglobin concentrations were 0.80 g/dL lower compared with patients with adequate 25OHD levels (50.0-100 nm). Hemoglobin levels were not significantly different at 25OHD levels above 100 nm compared with 50.0-100 nm. In multivariable-adjusted logistic regression analyses, the odds ratios for anemia of the groups with severe and moderate vitamin D deficiency (12.5-29.9 nm) were 1.70 (95% CI:1.09-2.63) and 1.41 (95% CI:1.02-1.96), respectively, compared with patients who had circulating 25OHD levels of 75-100 nm. Prevalence of deficient circulating 25OHD levels was highest in anemia of chronic kidney disease.

CONCLUSION

This cross-sectional study demonstrates an independent association between vitamin D status and anemia risk with optimal 25OHD levels of 75-100 nm. Randomized controlled trials are needed to clarify whether this association is causal.

Serum 25-hydroxyvitamin D levels in restless legs syndrome patients

OBJECTIVE

Restless legs syndrome is characterised by discomfort during rest and an urge to move the limbs that is accompanied by abnormal sensations. Studies on disease pathophysiology have focused on dopaminergic dysfunction. Vitamin D may play an important role in dopamine function, but the role of vitamin D in restless legs syndrome has not been examined. We compared the serum vitamin D levels of RLS patients and matched controls and explored the correlation of plasma vitamin D levels with disease severity.

PATIENTS/METHODS

We measured serum 25-hydroxyvitamin D levels in 36 patients with restless legs syndrome and compared them to 38 healthy control subjects.

RESULTS

The mean serum 25-hydroxyvitamin D levels were 7.31±4.63 ng/mL in female patients with restless legs syndrome and 12.31±5.27 ng/mL in female control subjects (p=0.001). We found a significant inverse correlation between vitamin D levels and disease severity in females (p=0.01, r=-0.47).

CONCLUSION

The mean serum vitamin D levels were lower in female patients with restless legs syndrome. Low vitamin D levels may cause dopaminergic dysfunction in restless legs syndrome patients. Further studies are required to confirm these results.

Study on the distribution of radioactive trace elements in vitamin D-overloaded rats using the multitracer technique

The uptake and distribution of radioisotopes of beryllium, calcium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, zinc, gallium, arsenic, strontium and barium in vitamin D (VD)-overloaded rats were investigated and compared with those in control rats, using the multitracer technique. Each element revealed its characteristic distribution among various organs in control and VD-overloaded rats. For some elements, such as cobalt and chromium, the distribution patterns in them were significantly different. These results are discussed in terms of the metabolism of the elements in rats.

Effects of micronutrients on metal toxicity

There is growing evidence that micronutrient intake has a significant effect on the toxicity and carcinogenesis caused by various chemicals. This paper examines the effect of micronutrient status on the toxicity of four nonessential metals: cadmium, lead, mercury, and arsenic. Unfortunately, few studies have directly examined the effect of dietary deficiency or supplementation on metal toxicity. More commonly, the effect of dietary alteration must be deduced from the results of mechanistic studies. We have chosen to separate the effect of micronutrients on toxic metals into three classes: interaction between essential micronutrients and toxic metals during uptake, binding, and excretion; influence of micronutrients on the metabolism of toxic metals; and effect of micronutrients on secondary toxic effects of metals. Based on data from mechanistic studies, the ability of micronutrients to modulate the toxicity of metals is indisputable. Micronutrients interact with toxic metals at several points in the body: absorption and excretion of toxic metals; transport of metals in the body; binding to target proteins; metabolism and sequestration of toxic metals; and finally, in secondary mechanisms of toxicity such as oxidative stress. Therefore, people eating a diet deficient in micronutrients will be predisposed to toxicity from nonessential metals.

The role of vitamin D in toxic metal absorption: a review

Vitamin D increases intestinal calcium and phosphate absorption. Not so well known, however, is that vitamin D stimulates the co-absorption of other essential minerals like magnesium, iron, and zinc; toxic metals including lead, cadmium, aluminum, and cobalt; and radioactive isotopes such as strontium and cesium. Vitamin D may contribute to the pathologies induced by toxic metals by increasing their absorption and retention. Reciprocally, lead, cadmium, aluminum, and strontium interfere with normal vitamin D metabolism by blocking renal synthesis of 1,25-dihydroxyvitamin D. This is the first review of the role of the vitamin D endocrine system in metal toxicology.

Hypothesis: etiology of atherosclerosis and osteoporosis: are imbalances in the calciferol endocrine system implicated?

Atherosclerosis and osteoporosis are currently considered unrelated diseases. Osteoporosis involves bone calcium (Ca) loss and predominantly affects females after menopause. Atherosclerosis is an illness predominantly affecting males, and is primarily characterized by abnormal lipid metabolism. However, pathological calcification of the arterial wall is an underlying feature of atherosclerosis. Ca homeostasis is thus important in atherosclerosis as well as in osteoporosis. Men also develop osteoporosis although at a later age than women, and, as osteoporosis progresses in women, there is an accompanying calcification of arteries leading to increased incidence of atherosclerosis in aging women. Thus, during old age, both atherosclerosis and osteoporosis are prevalent in both males and females. The dramatic increase in atherosclerosis among women as they develop osteoporosis suggests that the two illnesses may be more closely related than previously realized. The use of vitamin D as a food supplement coincides with epidemic onsets of atherosclerosis and osteoporosis, and excess vitamin D induces both conditions in humans and laboratory animals. These observations suggest a role for chronic vitamin D excess in the etiology of the two illnesses. Magnesium (Mg) deficiency, nicotine, and high dietary cholesterol are contributing factors that accentuate adverse effects of vitamin D.

Interrelationship of dietary vitamin D3 with zinc and iron in young turkeys

Three experiments were conducted with Large White turkeys to four weeks of age. The interrelationship of zinc and vitamin D3 was studied in two experiments. Iron and vitamin D3 were involved in one experiment. One group of ten male and one group of ten female poults were randomly assigned to each treatment within an experiment. All experiments involved a factorial arrangement of two dietary variables, D3 and either zinc or iron. For example, all possible combinations of four zinc levels; 31, 46, 76 and 106 p.p.m. and three vitamin D3 levels; 600, 1200, and 3600 I.C. units/kg. were fed in the second zinc experiment. Significant (P less than 0.05) weight gain differences occurred among both zinc and D3 levels in this experiment. Four week body weights were 356, 436, 459 and 444 g., respectively, for Zn levels; and 409, 410 and 452 g., respectively, for D3 levels. Significant (P less than 0.05) interactions occurred between dietary zinc and D3 levels, and between iron and D3 levels relative to body weight gain, Vitamin D3 tended to increase tibia zinc levels in poults receiving higher zinc levels; the opposite occurred with lower levels of the element. Zinc level in feces was decreased with vitamin D3. Hemoglobin level was not influenced by D3 but was increased by iron.

Vitamin D and manganese in the nutrition of the chick

1. In two experiments with chicks given diets of different manganese content, the effects of vitamin D on the Mn contents of bone and liver and on the retention of54Mn in bone, liver and the whole body were determined.

2. Vitamin D slightly increased the Mn content of dry fat-free bone but the proportion of Mn to ash remained unchanged and the Mn content of bone was influenced much more by the level of dietary Mn than by the presence of vitamin D.

3. Vitamin D, when given over a 3-week period, increased slightly the Mn content of the liver, but again the level of dietary Mn had a greater effect than the presence of vitamin D.

4. The retention of an oral dose of54Mn was not uniformly influenced by vitamin D, but in birds given the hign-Mn diet retention was reduced by vitamin D, indicating a decrease in the turnover of Mn.