Introduction: There is emerging evidence on the widespread tissue effects of vitamin D.
Aims: To formulate a position statement on the role of vitamin D in postmenopausal women.
Materials and methods: Literature review and consensus of expert opinion.
Results and conclusions: Epidemiological and prospective studies have related vitamin D deficiency with not only osteoporosis but also cardiovascular disease, diabetes, cancer, infections and neurodegenerative disease. However the evidence is robust for skeletal but not nonskeletal outcomes where data from large prospective studies are lacking. The major natural source of vitamin D is cutaneous synthesis through exposure to sunlight with a small amount from the diet in animal-based foods such as fatty fish, eggs and milk. Vitamin D status is determined by measuring serum 25-hydroxyvitamin D [25(OH)D] levels. Optimal serum 25(OH)D levels are in the region of 30-90 ng/mL (75-225 nmol/L) though there is no international consensus. Levels vary according to time of the year (lower in the winter), latitude, altitude, air pollution, skin pigmentation, use of sunscreens and clothing coverage. Risk factors for low serum 25(OH)D levels include: obesity, malabsorption syndromes, medication use (e.g. anticonvulsants, antiretrovirals), skin aging, low sun exposure and those in residential care. Fortified foods do not necessarily provide sufficient amounts of vitamin D. Regular sunlight exposure (without sunscreens) for 15 min, 3-4 times a week, in the middle of the day in summer generate healthy levels. The recommended daily allowance is 600 IU/day increasing to 800 IU/day in those aged 71 years and older. Supplementation can be undertaken with either vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol) with monitoring depending on the dose used and the presence of concomitant medical conditions such as renal disease.
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