BACKGROUND Analogues of vitamin D3 are extensively used in the treatment of various illnesses, such as osteoporosis, inflammatory skin diseases, and cancer. Functional testing of new vitamin D3 analogues and formulations for improved systemic and topical administration is supported by sensitive screening methods that allow a comparative evaluation of drug properties. As a new tool in functional...

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...

In swine nutrition, little is known about vitamin requirements for reproductive processes and bone health, especially vitamin D. Supplemental vitamin D is usually added to animal feed as cholecalciferol (vitamin D3), which is transported to the liver and hydroxylated to 25-hydroxycholecalciferol (25(OH)D3), and this metabolite has become commercially available for swine nutrition. Recently, the...

OBJECTIVE The positive short-term effects of postmenopausal hormone replacement therapy (HRT) on serum lipids are well known, but it has been suggested that they vanish with time. Cholecalciferol (vitamin D3) is widely used to prevent postmenopausal osteoporosis but the influence of vitamin D3 on serum lipids is poorly known. The long-term effects of HRT and vitamin D3 on the concentrations of ...

We report a rare case of Albright's syndrome associated with both a soft-tissue myxoma and hypophosphataemic osteomalacia. Renal tubular function was preserved, except for glycosuria. Serum levels of 1,25(OH)2 vitamin D3 were normal. Excision of the myxoma did not influence the biochemical abnormalities, nor did standard doses of vitamin D3 or 1 alpha-OH vitamin D3. The previously reported case...

Supplemental vitamin D is available in 2 distinct forms: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Pharmacopoeias have officially regarded these 2 forms as equivalent and interchangeable, yet this presumption of equivalence is based on studies of rickets prevention in infants conducted 70 y ago. The emergence of 25-hydroxyvitamin D as a measure of vitamin D status provides a...

Vitamin D is a fat-soluble prohormone and can be acquired by humans through cutaneous photosynthesis, diet or supplements. There are two forms of vitamin D from the above three sources: vitamin D2 and vitamin D3. Vitamin D2 is naturally found in plants like sun-dried mushrooms (e.g. shiitake mushrooms), while vitamin D3 is synthesised in human skin and is present in vitamin D-rich food of anima...

Vitamin D plays a critical role in skeletal homeostasis. Vitamin D supplementation is used worldwide to maintain optimal bone health, but the most appropriate level of supplementation remains controversial. This study aimed to determine the effects of varying doses of dietary vitamin D3 on the mechanical properties and morphology of growing bone. Eight-week-old female mice were supplied with on...

BACKGROUND Considering the suggested link between vitamin D insufficiency and several chronic diseases, attention should be given to approaches for improving vitamin D status. Elderly subjects are regarded as a high-risk group for developing an insufficient vitamin D status. Socioeconomic, dietary, lifestyle and environmental factors are considered as influencing factors, whereupon sex differen...

In calcium homeostasis, vitamin D3 is a potent serum calcium-raising agent which in vivo regulates both calcitonin (CT) and parathyroid hormone (PTH) gene expression. Serum calcium is the major secretagogue for CT, a hormone product whose biosynthesis is the main biological activity of thyroid C-cells. Taking advantage of this regulatory mechanism, long-term vitamin D3-induced hypercalcemia has...