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Adequate Vitamin D Status (adequate + vitamin_d_status)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Prevalence of 25(OH) vitamin D (calcidiol) deficiency at time of renal transplantation: a prospective study

CLINICAL TRANSPLANTATION, Issue 6 2007
D.M. Sadlier
Abstract:, 25(OH) Vitamin D (calcidiol) is the major circulating form of vitamin D and is considered the most reliable measure of vitamin D status. Adequate vitamin D status is important for bone health but there is increasing evidence that low serum concentrations of calcidiol (<30 ng/mL) are associated with many adverse health outcomes in the general population. Little is known about calcidiol status at the time of renal transplantation, a period when bone loss is greatest and immunosuppression is highest. We prospectively measured serum calcidiol and parathyroid hormone immediately after transplant from March 2005 onwards. Of 112 patients studied, 29% had calcidiol deficiency (<10 ng/mL), 59% had calcidiol insufficiency (10,29 ng/mL) and only 12% of patients had a normal calcidiol concentration (>30 ng/mL). The prevalence of calcidiol deficiency in black recipients was extremely high at 41%. Serum calcidiol tended to be lower in winter than other seasons. In conclusion, the prevalence of 25(OH) vitamin D (calcidiol) deficiency/insufficiency at the time of renal transplant is very high. The clinical effects of this deficiency/insufficiency deserve further study. [source]

Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 4 2010
Brian L. Diffey
Background/purpose: The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. Methods: The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. Results: It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health. Conclusions: Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status. [source]

REVIEW ARTICLE: Reducing fracture risk with calcium and vitamin D

CLINICAL ENDOCRINOLOGY, Issue 3 2010
Paul Lips
Summary Studies of vitamin D and calcium for fracture prevention have produced inconsistent results, as a result of different vitamin D status and calcium intake at baseline, different doses and poor to adequate compliance. This study tries to define the types of patients, both at risk of osteoporosis and with established disease, who may benefit from calcium and vitamin D supplementation. The importance of adequate compliance in these individuals is also discussed. Calcium and vitamin D therapy has been recommended for older persons, either frail and institutionalized or independent, with key risk factors including decreased bone mineral density (BMD), osteoporotic fractures, increased bone remodelling as a result of secondary hyperparathyroidism and increased propensity to falls. In addition, treatment of osteoporosis with a bisphosphonate was less effective in patients with vitamin D deficiency. Calcium and vitamin D supplementation is a key component of prevention and treatment of osteoporosis unless calcium intake and vitamin D status are optimal. For primary disease prevention, supplementation should be targeted to those with dietary insufficiencies. Several serum 25-hydroxyvitamin D (25(OH)D) cut-offs have been proposed to define vitamin D insufficiency (as opposed to adequate vitamin D status), ranging from 30 to 100 nmol/l. Based on the relationship between serum 25(OH)D, BMD, bone turnover, lower extremity function and falls, we suggest that 50 nmol/l is the appropriate serum 25(OH)D threshold to define vitamin D insufficiency. Supplementation should therefore generally aim to increase 25(OH)D levels within the 50,75 nmol/l range. This level can be achieved with a dose of 800 IU/day vitamin D, the dose that was used in succesfull fracture prevention studies to date; a randomized clinical trial assessing whether higher vitamin D doses achieve a greater reduction of fracture incidence would be of considerable interest. As calcium balance is not only affected by vitamin D status but also by calcium intake, recommendations for adequate calcium intake should also be met. The findings of community-based clinical trials with vitamin D and calcium supplementation in which compliance was moderate or less have often been negative, whereas studies in institutionalized patients in whom medication administration was supervised ensuring adequate compliance demonstrated significant benefits. [source]