Vitamin D

To test the effect of 25(OH)D(3) (HyD) compared to vitamin D(3) on serum 25-hydroxyvitamin D levels (25(OH)D), lower extremity function, blood pressure, and markers of innate immunity. Twenty healthy postmenopausal women with an average 25(OH)D level of 13.2 ± 3.9 ng/mL (mean ± SD) and a mean age of 61.5 ± 7.2 years were randomized to either 20 µg of HyD or 20 µg (800 IU) of vitamin D(3) per day in a double-blind manner...

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OBJECTIVES: To investigate the effects of personal calcium supplement use on cardiovascular risk in the Women's Health Initiative Calcium/Vitamin D Supplementation Study (WHI CaD Study), using the WHI dataset, and to update the recent meta-analysis of calcium supplements and cardiovascular risk. DESIGN: Reanalysis of WHI CaD Study limited access dataset and incorporation in meta-analysis with eight other studies. Data source WHI CaD Study, a seven year, randomised, placebo controlled trial of calcium and vitamin D (1g calcium and 400 IU vitamin D daily) in 36,282 community dwelling postmenopausal women...

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells...

OBJECTIVE: Determine prevalence of vitamin D deficiency (VDD) in a diverse group of women presenting for obstetrical care at two community health centers in South Carolina at latitude 32°N. METHODS AND DESIGN: Any pregnant woman presenting for care at 2 community health centers was eligible to participate. Sociodemographic and clinical history were recorded. A single blood sample was taken to measure circulating 25(OH)D as indicator of vitamin D status [25(OH)D < 20 ng/mL (50 nmol/L deficiency; <32 ng/mL (80 nmol/L) insufficiency]...

The objective was to determine the incidence of vitamin D deficiency, insufficiency, and sufficiency in African-American, Hispanic, and Caucasian pregnant women. Blood samples were taken from 154 African-American, 194 Hispanic, and 146 Caucasian women at <14 weeks of gestation; 25 hydroxyvitamin D levels (25(OH)D) levels were measured by radioimmunoassay. The mean 25(OH)D levels in African-American, Hispanic, and Caucasian pregnant women were 15.5 ± 7.2 (standard deviation), 24.1 ± 8.7, 29.0 ± 8...

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BACKGROUND: Vitamin D and related compounds have been used to prevent osteoporotic fractures in older people. This is the third update of a Cochrane review first published in 1996. OBJECTIVES: To determine the effects of vitamin D or related compounds, with or without calcium, for preventing fractures in post-menopausal women and older men. SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (to December 2012), the Cochrane Central Register of Controlled Trials (2012, Issue 12), MEDLINE (1966 to November Week 3 2012), EMBASE (1980 to 2012 Week 50), CINAHL (1982 to December 2012), BIOSIS (1985 to 3 January 2013), Current Controlled Trials (December 2012) and reference lists of articles...

BACKGROUND: Vitamin D insufficiency is associated with many disorders, leading to calls for widespread supplementation. Some investigators suggest that more clinical trials to test the effect of vitamin D on disorders are needed. METHODS: We did a trial sequential meta-analysis of existing randomised controlled trials of vitamin D supplements, with or without calcium, to investigate the possible effect of future trials on current knowledge. We estimated the effects of vitamin D supplementation on myocardial infarction or ischaemic heart disease, stroke or cerebrovascular disease, cancer, total fracture, hip fracture, and mortality in trial sequential analyses using a risk reduction threshold of 5% for mortality and 15% for other endpoints...

One of the factors contributing to the increased risk of developing premature atherosclerosis is low plasma concentrations of high-density lipoprotein (HDL) cholesterol. Multiple potential mechanisms account for the cardioprotective effects of HDL and its main protein apolipoprotein A-I (apo A-I). Diet has an important role in modulating HDL cholesterol level. The widespread use of nutritional supplements may also alter the biology of HDL. In this review, we discuss the effect of select nutritional supplements on serum HDL cholesterol and apo A-I levels...

Although many studies have investigated meat and total fat in relation to pancreatic cancer risk, few have investigated dairy, fish and specific fatty acids (FAs). We evaluated the association between intake of meat, fish, dairy, specific FAs and related nutrients and pancreatic cancer. In our American-based Mayo Clinic case-control study 384 cases and 983 controls frequency matched on recruitment age, race, sex and residence area (Minnesota, Wisconsin or Iowa, USA) between 2004 and 2009. All subjects provided demographic information and completed 144-item food frequency questionnaire...

Vitamin D signaling not only controls calcium (Ca2+) and phosphorus uptake and transport, but also correlates with neurocognitive decline and neurodegenerative diseases. Almost all actions of Vitamin D are mediated by the transcription factor, vitamin D receptor (VDR), which has been widely identified in the central nervous system. Although previous studies have substantially advanced the understanding of the action of VDR in the brain, much remains unknown concerning how VDR relates to stress. Multiple lines of evidence indicate that the downregulation of L-type voltage-sensitive Ca2+-channels α-1C (LVSCC-A1C) by vitamin D in hippocampal neurons is able to reduce the influx and excitotoxic effects of Ca2+ to neurons...

Vitamin D3 is made in the skin from 7-dehydrocholesterol under the influence of UV light. Vitamin D2 (ergocalciferol) is derived from the plant sterol ergosterol. Vitamin D is metabolized first to 25 hydroxyvitamin D (25OHD), then to the hormonal form 1,25-dihydroxyvitamin D (1,25(OH)2D). CYP2R1 is the most important 25-hydroxylase; CYP27B1 is the key 1-hydroxylase. Both 25OHD and 1,25(OH)2D are catabolized by CYP24A1. 1,25(OH)2D is the ligand for the vitamin D receptor (VDR), a transcription factor, binding to sites in the DNA called vitamin D response elements (VDREs)...

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AIM: To evaluate the association of vitamin D (VD) deficiency with gonadotropins and sex hormone in obese and non-obese women with polycystic ovary syndrome (PCOS). METHODS: Of the total of 140 women, thirty obese and thirty nonobese, aged 20-40 years, were included in the study. Inclusion criteria were the women with normal level of thyroid-stimulating hormone (TSH), prolactin (PRL), parathyroid hormone (PTH), and calcium, and those who had not received any medication or VD supplementation within the last 6 months...

Vitamin D is thought to protect the cardiovascular system, although its role is not completely clear. The beneficial effect may occur by vascular calcification inhibition through blockage of both inflammatory cytokines and adhesion molecules. Moreover, calcitriol is a renin negative regulator, interfering in renin-angiotensin-aldosterone system (RAAS) and limiting the production of angiotensin II, an inflammatory and atherogenic cytokine implicated in the development of atheromatous plaques. Epidemiological studies showed an association between osteoporosis and atherosclerosis, which suggests the existence of common underlying mechanisms...

OBJECTIVE: Our goal was to compare direct quantitation of circulating free 25-hydroxyvitamin D (25(OH)D)levels to calculated free 25(OH)D levels and their relationships to intact PTH (iPTH), a biomarker of 25(OH)D effect, in humans with a range of clinical conditions. PATIENTS AND METHODS: Serum samples and clinical data were collected from 155 people: 111 without cirrhosis or pregnancy (comparison group), 24 cirrhotic patients with albumin <2.9 g/dL, and 20 pregnant women (second and third trimester)...

BACKGROUND: Although no gold standard exists, liquid chromatography tandem mass spectrometry (LC-MS/MS) is a precise and accurate method for the analysis of plasma 25-hydroxyvitamin D (25(OH)D). Immunoassays are more readily available and require small volume sampling, ideal for infant testing. The objective was to compare two commercially available immunoassays for measuring circulating 25(OH)D concentration in infant plasma against LC-MS/MS. METHODS: Capillary blood samples from 103 infants were analyzed for plasma 25(OH)D using an enzyme immunoassay (EIA, Octeia, IDS Ltd...

OBJECTIVE: Burn patients are at risk of hypovitaminosis D. Optimal vitamin D (VD) intakes are not defined in burn nutrition guidelines and studies mostly focused on ergocalciferol (VD2) supplementation in burn children. Aim of our study was to describe adult burns VD status, to measure effects of our cholecalciferol (VD3) supplementation on VD metabolism during acute burn care, and to assess correlation between FGF23 and C-reactive protein (CRP). DESIGN: Cohort study...

CONTEXT: Randomized controlled trials (RCTs) investigating the efficacy of vitamin D (Vit D) in depression provided inconsistent results. OBJECTIVE: We aim to summarize the evidence of RCTs to assess the efficacy of oral Vit D supplementation in depression compared to placebo. DATA SOURCES: We searched electronic databases, two conference proceedings, and gray literature by contacting authors of included studies. STUDY SELECTION: We selected parallel RCTs investigating the effect of oral Vit D supplementation compared with placebo on depression in adults at risk of depression, with depression symptoms or a primary diagnosis of depression...