1. The term vitamin D is used for a range of closely related steroid compounds which possess the property of preventing or curing vitamin D deficiency. These include alfacalcidol (1α-hydroxyvitamin D3), calcifediol (25-hydroxyvitamin D3), calcitriol (1α,25 dihydroxy-vitamin D3), cholecalciferol (vitamin D3), dihydrotachysterol and ergocalciferol (vitamin D2 or calciferol). In veterinary medicin...

To evaluate the role of vitamin D3 during gestation and lactation of sows, 2 independent experiments were performed with the aim of investigating sow reproductive performance, milk composition (study 1 only), and changes in blood status of 25-hydroxycholecalciferol (25-OH-D3), 1,25-dihydroxycholecalciferol (1,25-(OH)2-D3; study 2 only), minerals, and bone markers of sows during gestation and la...

The absorption of simultaneously administered equimolar doses of 14C vitamin D3 and 3H 25 hydroxyvitamin D3 (25-OH-D3) has been studied in controls and patients with a variety of gastrointestinal disorders. As assessed from peak radioactivity in the serum and from faecal excretion of radioactivity, malabsorption of both vitamin D3 and 25-OH-D3 occurred in patients with steatorrhoea. Malabsorpti...

1,25-Dihydroxyvitamin D3 is believed to mediate the regulation of calcium metabolism by a steroid hormone receptor mechanism. We now demonstrate that phosphorylation of the 1,25-dihydroxyvitamin D3 receptor occurs rapidly in embryonic chick duodenal organ culture in response to 1,25-dihydroxyvitamin D3. Phosphorylation of the receptor is strongly induced within 1 h by 1,25-dihydroxyvitamin D3 a...

We describe a patient with early diagnosed cystinosis who presented with nephrogenic diabetes insipidus in addition to proximal tubular dysfunction. Another feature in this patient was abnormally low serum concentration of 24,25 dihydroxy vitamin D3 (24,25(OH)2D3) with normal 25 hydroxy vitamin D3 (25(OH)D3) and relatively low 1,25 dihydroxy vitamin D3 (1,25(OH)2D3).

INTRODUCTION Incomplete human extravillous trophoblast (EVT) invasion of the decidua and maternal spiral arteries is characteristic of pre-eclampsia, a condition linked to low maternal vitamin D status. It is hypothesized that dysregulated vitamin D action in uteroplacental tissues disrupts EVT invasion leading to malplacentation. METHODS This study assessed the effects of the active vitamin ...

BACKGROUND The relative potency of 25-hydroxyvitamin D3 to vitamin D3 needs to be better defined so that food-composition tables can better reflect the true vitamin D nutritive value of certain foods. OBJECTIVE We performed a randomized, controlled intervention study in apparently healthy, free-living adults to investigate whether the intake of 25-hydroxyvitamin D3 is 5 times more potent in r...

There is considerable interest in developing highly selective dopamine (DA) D3 receptor ligands for a variety of mental health disorders. DA D3 receptors have been implicated in Parkinson's disease, schizophrenia, anxiety, depression, and substance use disorders. The most concrete evidence suggests a role for the D3 receptor in drug-seeking behaviors. D3 receptors are a subtype of D2 receptors,...

1,25-Dihydroxyvitamin D3, the hormonal form of vitamin D3, promotes the differentiation of HL-60 human promyelocytic leukemia cells into monocytes. Differentiation changes include the induction of phagocytosis, the initiation of nitroblue tetrazolium-reducing activity, and the appearance of nonspecific acid esterase. We have found that the 24-homo- and 26-homo-1,25-dihydroxyvitamin D3 and their...