IDENTIFICATION OF THE POPULATION AT RISK FOR DEVELOPING DEFICIENCY/INSUFFICIENCY OF VITAMIN D. PREVENTATIVE DOSES

Vitamin D is the regulator of mineral and bone metabolism. Its main source is synthesis in the skin due to the action of ultraviolet radiation. Nutritional status can be evaluated through serum levels of 25-hydroxyvitamin D; cut-off values are controversial, but there is current agreement to define Deficiency (< 10 ng/ml), which implies increased risk of rickets in children and osteomalacia in adults; Insufficiency ( 20-30 ng/ml), which might indicate low sustrate for the synthesis of 1,25 dihydroxyvitamin D, and which can be also suspected when serum levels of PTH are elevated; Minimal required levels: for the prevention of osteoporotic fractures. Groups at highest risk of developing vitamin D deficiency are children less than one year of age, and elderly adults (> 65 years). Other risk factors are: dark skin, skin usually covered with clothing due to religious beliefs, living at high latitudes, and Winter. Daily oral doses of vitamin D effective to prevent deficiency vary according to age, risk factors, time of administration, and type of vitamin used (D-2 or D-3). Current research focuses on the role of vitamin D sufficiency on the attainment of peak bone mass, and optimal levels of supplementation as part of other anti - osteoporotic treatments. As a final conclusion, both the evaluation and the correction of vitamin D nutritional status are important issues, taking into account present discrepancies about adequate or optimal serum levels, and the most effective preventative doses.