[Vitamin D status in women living in Buenos Aires]

Bone loss has both age-related and menopausal components. The causes of age-related bone loss are multifactorial. In order to establish vitamin D status in women in our city (34 degrees S), calcidiol levels were assessed in 357 ambulatory women aged 40-90 years. One hundred and eighty were evaluated during summer time and 177 during winter time. We also evaluated intact PTH values in a subgroup of 231 women and this allowed us to document the prevalence of secondary hyperparathyroidism. Summer levels of calcidiol were significantly higher than in winter: 25.3 +/- 8.5 vs 21.3 +/- 7.4 ng/ml (p < 0.001). We found 4.4% of calcidiol levels < 10 ng/ml (2.2% in summer and 6.6% in winter). Prevalence of calcidiol between 10-20 ng/ml reached 67% in winter and went down to 25% during summer. Prevalence of secondary hyperparathyroidism was 5.2%. Even though prevalence of vitamin D deficiency was low, a great proportion of ambulatory women had calcidiol levels between 10-20 ng/ml. These values would not be sufficient for elderly people and could result in increased calcium mobilisation and further bone loss.