It has been shown that mammalian cytochrome P450scc can metabolize vitamin D3 to 20-hydroxyvitamin D3 (20(OH)D3) and 20,22(OH)2D3. To define the biological significance of this pathway, we tested the effects of 20(OH)D3 on the differentiation program of keratinocytes and on the expression of enzymes engaged in vitamin D3 metabolism. Immortalized HaCaT and adult human epidermal keratinocytes wer...

Three experiments were conducted to determine whether feeding 25-hydroxyvitamin D3 (25-OH 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 wer...

The metabolism of [3H]vitamin D3 in hepatectomized vitamin D-deficient rats has been studied. Hepatectomy drastically disrupts vitamin D3 metabolism as revealed by prolonged high levels of [3H] vitamin D3 in the plasma compartment even 12 h after dose in contrast to sham-operated controls. Some conversion of [3H] vitamin D3 to [3H]25-hydroxyvitamin D3 was detected in hepatectomized rats, but th...

We previously found a weak response in serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations when dogs were supplemented with oral vitamin D3 (D3). In the present study, we determined the relative potency of oral 25(OH)D3 compared with D3 for increasing vitamin D status in dogs with low serum 25(OH)D concentrations. Four male and three female, 4-year-old, intact, lean, genetically related, Chine...

Vitamin D deficiency is a global health problem. This study aimed to investigate the efficacy of ultraviolet (UV) B radiation for improving vitamin D3 content of eggs and meat. In a two-factorial design hens that received diets with 0 (-D3) or 3,000 IU (+D3) vitamin D3/kg were non-exposed (-UVB) or exposed to UVB radiation (+UVB) for 3 h daily over 4 weeks. Data show that UVB radiation was very...

Background and Objectives: Previous research has established that Vitamin D3 (Cholecalciferol) deficiency is considered to be a highly prevalent nutritional problem worldwide. Data from National Food and Nutrition Surveillance Program (2015) revealed that prevalence of vitamin D3 deficiency in Iran is more than 70% of the population. Vegetable oils are considered to be potential candidates for ...

While vitamin D3 is recognized as a neuroactive steroid affecting both brain development and function, efficient analytical method in determining vitamin D3 metabolites in the brain tissue is still lacking, and the relationship of vitamin D3 status between serum and brain remains elusive. Therefore, we developed a novel analysis method by using high performance liquid chromatography-tandem mass...

In this study, we characterized the effects of 25-hydroxyvitamin D3 (25-OH D3) and manipulated dietary cation-anion difference (DCAD) on the performance, urine pH, serum constituents, carcass traits, tissue residual vitamin D and its metabolites, beef tenderness, and mRNA and protein concentrations of Ca-dependent proteinases in LM using 24 cull native Korean cows. The cows were divided into 3 ...