Dietary intake of vitamin D includes vitamin D3 (vitD3), 25-hydroxyvitamin D3 (25OH-D3), and vitamin D2 (vitD2). However, the bioactivity of the different species has not been scientifically established. The hypothesis in this study was that vitD3, 25OH-D3, and vitD2 have an equal effect on 25-hydroxyvitamin D in serum (vitamin D status). To test our hypothesis, we performed a randomized, cross...

Dietary supplements that prevent bone loss at the hip and that can be applied safely in the elderly are likely to reduce hip fractures. A daily dietary supplement of 750 mg calcium or 15 microg 25OH vitamin D3 on bone loss at the hip and other sites, bone turnover and calcium-regulating hormones were studied over 4 yr in elderly volunteers using a randomized, double-blind, placebo-controlled tr...

Three experiments were conducted to determine whether feeding 25-hydroxyvitamin D3 (25OH D3) or 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D3) improves the tenderness of longissimus dorsi (LD), semimembranosus (SM), and infraspinatus (IF) muscles similar to supplemental vitamin D3 without leaving residual vitamin D3 and its metabolites in muscle. In the first two experiments, 24 crossbred steers were...

Abstract The current objective was to develop imaging techniques characterize osteochondrotic-like lesions (OC-lesions) and evaluate the efficacy of dietary interventions promote lesion regression prevent lameness. Pigs (n=76) were weaned (~6kg) fed 1 2 nursery diets for 3-wk with no supplemental vitamin D, (-D, n=60) or 280 IU D3/kg (+D3, n=20). Following nursery, +D pigs standard (+Ctl) -D al...

An essential element of the innate immune response to injury is the capacity to recognize microbial invasion and stimulate production of antimicrobial peptides. We investigated how this process is controlled in the epidermis. Keratinocytes surrounding a wound increased expression of the genes coding for the microbial pattern recognition receptors CD14 and TLR2, complementing an increase in cath...

An in vitro assay of mammalian 25-hydroxyvitamin D3 laand 24R-hydroxylases in kidney has been developed. It had been suggested that 25-hydroxyvitamin D binding protein present in mammalian blood and tissues inhibits the enzyme activities in cell-free preparations by binding the substrate 25-hydroxyvitamin D3 more strongly than the hydroxylases bind it. This inhibitory effect is overcome by the ...

There has been increasing interest in recent years in the prevalence of low 25-hydroxy (OH) vitamin D concentrations in different human populations [1, 2]. There are 2 forms of vitamin D: cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2). Vitamin D3 is manufactured through the photoisomerization of 7-dehydrocholesterol to pre-vitamin D3, which then undergoes a temperature-dependent r...

OBJECTIVE To determine whether 25OH-D levels in the follicular fluid (FF) of infertile women undergoing IVF demonstrate a relationship with IVF cycle parameters and outcome, hypothesizing that levels of 25OH-D in body fluids are reflective of vitamin repletion status. DESIGN Prospective cohort study. SETTING Academic tertiary care center. PATIENT(S) Eighty-four infertile women undergoing ...

Objective: Psoriasis is an inflammatory disease of the skin and the joints. Psoriatic patients sometimes suffer from vitamin D deficiency and hypocalcemia. The aim of our study was to evaluate the level of calcium and vitamin D in patients with psoriasis. Materials and Methods: In this analytical cross sectional study, 110 cases of psoriasis that were referred to Shohadaye Mehrab clinic during...