Introduction: In serum, 25-hydroxy-vitamin D (25(OH)D) can be found in two forms, namely 25(OH)D2 and 25(OH)D3. We recently published a mathematical method to estimate the 25(OH)D2 recovery without spiking the samples. Since then, new “total” vitamin D immunoassays have appeared on the market (Roche “Total” vitamin D, Siemens Centaur vitamin D “total”, “total” vitamin D on DiaSorin Liaison XL, ...

[This corrects the article DOI: 10.1155/2014/691679.].

OBJECTIVE — Accumulating research suggests low-circulating vitamin D concentrations, i.e., 25-hydroxyvitamin-D [25(OH)D], may be associated with an increased prevalence of metabolic syndrome; however, previous studies have not accounted for parathyroid hormone (PTH) levels. We examined the association of 25(OH)D and PTH with the prevalence of metabolic syndrome in a community-based cohort of ol...

The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant,...

A randomized double-blind controlled trial of the effect of vitamin D supplementation on the abilities of elderly hospital patients to carry out basic activities of daily life is described. Those patients included in the trial had plasma 25-hydroxyvitamin D concentrations which were low or low normal as judged by the normal range in young adults. After 2 to 9 months on the trial there was no si...

Citation: Guggenheim JA, Williams C, Northstone K, et al. Does vitamin D mediate the protective effects of time outdoors on myopia? Findings from a prospective birth cohort. Invest Ophthalmol Vis Sci. 2014;55:8550–8558. DOI:10.1167/iovs.14-15839 PURPOSE. More time outdoors is associated with a lesser risk of myopia, but the underlying mechanism is unclear. We tested the hypothesis that 25-hydro...

Circulating 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with both higher and lower risk of prostate cancer (PCa), whereas elevated levels of circulating calcium has been related to higher risks. However, there are few studies that account for effects of both calcium and 25(OH)D concentrations on incident PCa in a black population. We examined these relationships in a case-...

Background: The effect of season on vitamin D status is often overlooked in studies of optimal vitamin D concentrations and in

OBJECTIVE To assess the relationship between low maternal serum 25-hydroxyvitamin D levels and gestational diabetes mellitus in Turkish pregnant women according to the severity of 25-hydroxyvitamin D deficiency and assess intact parathyroid hormone levels in women with gestational diabetes mellitus and controls with low and sufficient 25-hydroxyvitamin D levels. METHODS We analyzed serum 25-h...