Two human hepatoma cell lines, Hep G2 and Hep 3B, were screened for vitamin D3-25-hydroxylase enzyme activity by incubation with radioactive vitamin D3. A compound co-chromatographing with 25-OH-D3 was synthesized in both cell lines but its rate of synthesis was tenfold greater in Hep 3B than in Hep G2 cells. The identity of the compound was confirmed by comparing its chromatographic properties...

There are numerous scientific studies on vitamin D3 reported to have many important roles viz. in bone metabolism, osteoporosis, immunity, and useful in several diseases, e.g., cancers, cardio-vascular, and neurodegenerative diseases. Surprisingly, there is little information available about the concentration of 25-hydroxyvitamin D3 in the blood, which is the best indicator of vitamin D3 status...

The prevention of neonatal rickets by oral supplementation with vitamin D2 (ergocalciferol) has tended to obscure our ignorance of the natural mechanism by which young mammals receive an adequate supply of vitamin D. To investigate the possibility of specific intrauterine transfer and storage of vitamin D in fetal tissues, vitamin D-deficient female rats were given depot injections of 3H- or 14...

OBJECTIVE Despite the suggested role of vitamin D in the prevention of diabetes and cardiovascular disease or its risk factors, the evidence is not consistent and there is a paucity of randomized controlled trials in this field. We aimed to investigate the effect of 16-week daily vitamin D3 supplementation on glycated hemoglobin (HbA1c), fructosamine, body mass index (BMI), and serum lipids. ...

BACKGROUND Severe dengue disease is associated with high viral loads and overproduction of pro-inflammatory cytokines, suggesting impairment in the control of dengue virus (DENV) and the mechanisms that regulate cytokine production. Vitamin D3 has been described as an important modulator of immune responses to several pathogens. Interestingly, increasing evidence has associated vitamin D with d...

OBJECTIVES Systemic lupus erythematosus (SLE) is a multi-factorial autoimmune disease which may be characterized by T lymphocytes dysfunctions. Th17 cells have been identified as new effector cells, which play an important role in the pathogenesis. In recent years, immunomodulatory effect of vitamin D3 has been noticed. In the present experiment, the effect of vitamin D3 on the expression of IL...

Background: We investigated serum levels of 25-hydroxyvitamin D3 and the vitamin D receptor (VDR) gene polymorphisms (Fokl, Bsml) in Egyptian patients with Behçet’s disease (BD) and their relationship to disease manifestations and activity. Methods: We studied 45 patients with BD fulfilling the international study group criteria ISG for BD (1999) and 45 healthy, matched controls. We evaluated V...

Over a period of time, two vitamin D parent compounds were elucidated. Ergocalciferol (D2) is synthesized from ergosterol in many plants, whereas cholecalciferol (D3) is derived from 7-dehydrocholesterol in the skin of animals. Ultraviolet light transforms these compounds into 1, 25-diOH vitamin D3, the vitamin D metabolite generally considered the most active. Approximately 40 times more D2 is...

BACKGROUND Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disorder. Vitamin D has important roles both in the autoimmune response and in skeletal muscles. We determined the levels of 25-hydroxy vitamin D [25(OH)D] in patients with MG and in healthy subjects to determine whether vitamin D deficiency is present in MG and whether vitamin D supplementation has beneficial effects on fa...

Two new vitamin D metabolites were isolated in pure form from incubations of 53 nM 1,25-dihydroxyvitamin D3 with homogenates of small intestinal mucosa of vitamin D-replete chicks. The birds were injected intravenously with 8 to 9 nmol of 1,25-dihydroxyvitamin D3/100 g body weight 5 to 8 h before death. The isolation involved methanol-chloroform extraction and four successive chromatographic pr...