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).

Human dendritic cells (DC) can be differentiated from blood monocytes in the presence of GM-CSF and IL-4 and matured by lipopolysaccharide (LPS). Vitamin D3 inhibits the maturation of human DC measured by changes in surface expression of HLA-DR, CD14, CD40, CD80, CD83, and CD86. We here examine the function of vitamin D3 during DC maturation. One of the earliest changes to LPS-induced maturatio...

The competence of the duodenal 1ƒ¿, 25-(OH)2-D3 receptor system in embryonic chicks was studied in the reconstituted cytosol-chro matin system. The sucrose density gradient centrifugation following incubation of duodenal cytosol with 1x,25-dihydroxy-[3H]-vitamin D3 revealed that a cytosol 1x,25-dihydroxyvitamin D3 receptor existed in the duodenum of 18-day-old embryos. In the duodenum of 14-day...

BACKGROUND The three main vitamin D metabolizing enzymes, vitamin D3-25-hydroxylase (25-OHase, 25-hydroxylase), 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-OHase, 1alpha-hydroxylase) and 25-hydroxyvitamin D3-24-hydroxylase (24-OHase, 24-hydroxylase), have been described in malignant breast tissue. This in vitro study aimed to obtain more information regarding the regulation of these enzymes...

BACKGROUND Little if any cutaneous production of vitamin D3 occurs at latitudes above and below 35° N and 35° S during the winter months. It was postulated that those residing in tropics synthesize enough vitamin D3 year round. Several studies have documented the effect of latitude, season and time of the day on the cutaneous production of vitamin D3 in an ampoule model. Studies from India have...

Mushrooms exposed to sunlight or UV radiation are an excellent source of dietary vitamin D2 because they contain high concentrations of the vitamin D precursor, provitamin D2. When mushrooms are exposed to UV radiation, provitamin D2 is converted to previtamin D2. Once formed, previtamin D2 rapidly isomerizes to vitamin D2 in a similar manner that previtamin D3 isomerizes to vitamin D3 in human...

The role of the prohormone vitamin D3 in regulating calcium and phosphate metabolism in the intestine, kidney, and bone has been known for several decades. Recent studies have provided evidence that vitamin D3, may also play an important role in regulating metabolism in other organs, including heart. This role has been suggested by the identification of a specific receptor for 1,25-dihydroxyvit...

There is increasing evidence supporting dietary and alternative therapies for epilepsy, including the ketogenic diet, modified Atkins diet, and omega-3 fatty acids. Vitamin D3 is actively under investigation as a potential intervention for epilepsy. Vitamin D3 is fat-soluble steroid, which shows promise in animal models of epilepsy. Basic research has shed light on the possible mechanisms by wh...

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...