larly the oxidation of its side chain, has been investigated by many groups, the conjugates of D metabolites still remain poorly understood. Axelson1 and we2 have reported that 25-hydroxyvitamin D3 [25(OH)D3] 3-sulfate (S) is a major circulating metabolite in humans. Furthermore, we identified the monoglucuronides (G) of D compounds {vitamin D2, vitamin D3 (D3), 25hydroxyvitamin D2, 25(OH)D3, a...

Background—Patients with cystic fibrosis have several risk factors for the development of low bone mineral density (BMD). To identify the prevalence and clinical correlates of low BMD in adult patients with cystic fibrosis, densitometry was performed in 151 patients (83 men) aged 15–52 years. Methods—BMD was measured in the lumbar spine (L1–4) using dual energy x ray absorptiometry (DXA) and qu...

Normal bone metabolism clearly requires vitamin D, it is undisputed for its classic role in bone metabolism, calcium and phosphorus homeostasis. Recently, a worldwide focus has been directed on the extra-skeletal effects of this vitamin. The New York Times even called it the “wonder drug”. Vitamin D is obtained by synthesis in the skin after ultraviolet B exposure or through food consumption. A...

Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM 2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer’s disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM...

Although aluminum excess is an apparent pathogenetic factor underlying osteomalacia in dialysis-treated patients with chronic renal failure, the mechanism by which aluminum impairs bone mineralization is unclear. However, the observation that aluminum is present at osteoid-bone interfaces in bone biopsies of affected patients suggests that its presence at calcification fronts disturbs the cellu...

Background: Vitamin D binding protein (DBP) binds vitamin D and its plasma metabolites, including 25hydroxyvitamin D (25(OH)D), in the circulation. Only a small fraction circulates free (free 25(OH)D). Genetic variation of the GC gene, encoding DBP, has been associated with 25(OH)D concentrations. The roles of DBP and free 25(OH) D concentrations in the biological actions of vitamin D remain un...

The active form of vitamin D, 1,25-dihydroxvitamin D3 (1,25(OH)2D3), is a pleiotropic hormone whose actions include the regulation of calcium homeostasis, control of bone cell differentiation and modification of immune responses. Synthesis of 1,25(OH)2D3 from the major circulating metabolite, 25-hydroxyvitamin D3 (25(OH)D3), is catalysed by a mitochondrial cytochrome P450 enzyme, 25hydroxyvitam...

The report by Hyppönen and Power in this issue of the Journal (1) highlights a frustrating and regrettable situation for nutrition researchers. In the early 1970s, the same serum 25hydroxyvitamin D [25(OH)D] concentrations reported by Hyppönen and Power were thought to be indicative of “healthy” white adults in the United Kingdom (2). However, during those early years after the discovery of 25(...

Peripheral Artery Disease To the Editor: We wish to point out to readers who look casually through the Brief Review by Norman and Powell1 or who have access only to its abstract that the review is not relevant to vitamin D in the context of nutrition. Furthermore, the authors failed to present evidence that suggests that vitamin D may have cardiovascular benefits. The major difficulty with the ...

To the Editor: The major problem in measuring 25hydroxyvitamin D (25-OHD) is attributable to the molecule itself (1). Thus, an analytical method must be selected that will accurately estimate total circulating 25-OHD independent of the circulating concentrations of 25OHD2 and 25OHD3. Although HPLC remains the method of choice, many convergent data indicate that the 25-OHD RIA (DiaSorin Inc) sho...