High prevalence of vitamin D insufficiency in healthy elderly people living at home in Argentina

Objective: To evaluate the nutritional status of vitamin D in urban populations of healthy elderly people living at home, in different regions of Argentina. Design: Cross-sectional study. Subjects: In total, 386 ambulatory subjects over 65 y of age from seven cities ( between latitude 26degreesS and 55degreesS) were asked to participate between the end of winter and the beginning of spring. Of these, 369 accepted, 30 were excluded because of medical history or abnormal biochemical determinations. Finally, 339 subjects ( 226 women and 113 men) ( X+/-s. d.) (71.3 +/- 5.2 y) were included. Results: Serum 25OHD levels were lowest in the South ( latitude range: 41degreesS - 55degreesS): 14.2 +/- 5.6 ng/ml ( P<0.0001 vs North and Mid regions); highest in the North (26 degrees S - 27 degrees S): 20.7 +/- 7.4 ng/ml ( P<0.03 vs Mid, P<0.0001 vs South); and intermediate in the Mid region (33 degrees S - 34 degrees S) 17.9 +/- 8.2 ng/ml. Serum mid-molecule PTH (mmPTH) and 25OHD were inversely related: (r = - 0.24, P<0.001). A cutoff level of 25OHD at which serum mmPTH levels began to increase was established at 27 ng/ml. A high prevalence ( 87 - 52%) of subjects with 25OHD levels in the deficiency-insufficiency range ( 25OHD levels <20 ng/ml) was detected. Conclusion: This study shows that vitamin D deficiency/insufficiency in the elderly is a worldwide problem. Correction of this deficit would have a positive impact on bone health of elderly people.