HIGH PREVALENCE OF VITAMIN D DEFICIENCY IN 1048 ROMANIAN WOMEN WITH POSTMENOPAUSALOSTEOPOROSIS

摘要

Vitamin D deficiency and insufficiency are common medical problems worldwide as they are quite prevalent in both healthy adults and individuals with osteoporosis, hospitalized patients and free-living and institutionalized elderly. The lack of serum 25-hydroxy-vitamin D (25OHD) assays standardization, variability of reference population/and the use of different cut-off points have produced quite different prevalence reports from epidemiological studies.We investigated the vitamin D status (deficiency, insufficiency, sufficiency) in 1048 Romanian postmenopausal women with osteoporosis referred to our clinic for diagnosis and treatment in the last three years. Most patients were untreated with osteoporosis drugs and non-supplemented with vitamin D. In our country dietary sources of vitamin D are scarce and there is no fortification of food with vitamin D. We found a high prevalence of both vitamin D deficiency (25OHD < 10 ng/mL) - 22.23% and insufficiency (25OHD=10-30 ng/mL) - 61.26%. Our study also revealed a high prevalence of low vitamin D when using other cut-offs as reported in the literature. 83.49% had values lower than 30 ng/mL and 60.97% lower than 20 ng/mL. In this study we identified a serum 25OHD concentration of 35 ng/mL above which serum parathyroid hormone (PTH) concentration attains a plateau at about 35 pg/mL. The relation between serum PTH and 25OHD concentration was non-linear and a log-log diagram showed a very weak correlation. The prevalence of secondary hyperparathyroidism was 32.25% in the whole population studied. It ranged from 40% in the subgroup of serum 25OHD less than 10 ng/mL to less than 15% in patients with 25OHD higher than 30 ng/mL.In conclusion, in a representative osteoporosis population from Romania we found a very high prevalence of vitamin D deficiency and insufficiency whatever the cut-off used for definition.