Vitamin D status and its seasonal variations and association with parathyroid hormone concentration in healthy women in Riga.

UNLABELLED: The aim of the study was to describe the vitamin D status and its seasonal variations in women living in Riga, Latvia, to examine an association between the concentrations of plasma 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH), and to determine the threshold for plasma 25(OH)D above which there is no further suppression of PTH. MATERIAL AND METHODS: The data of 189 healthy Caucasian women were analyzed. The serum levels of 25(OH)D, PTH, and phosphorus were measured twice a year. All the participants were divided into 3 groups according to vitamin D supplementation and the reproductive status. RESULTS: The overall mean level of 25(OH)D was 32.8 ng/mL with significantly lower levels being in winter when compared with those in summer (28.2 ng/mL vs. 37.5 ng/mL, respectively; P<0.05). PTH was negatively associated with 25(OH)D. A threshold level of plasma 25(OH)D above which no further suppression of PTH occurred was found to be 38 ng/mL. Postmenopausal women not taking vitamin D supplements and without exposure to sunlight had 25(OH)D deficiency in winter and summer (92% and 88%, respectively). The most significant seasonal fluctuations were seen in the women of the reproductive age not taking vitamin D supplements and without exposure to sunlight, of which 47% had 25(OH)D deficiency in summer and 69% in winter. CONCLUSIONS: An optimal concentration of 25(OH)D was found to be 38 ng/mL. According to this definition, 70.4% of all the healthy women were classified as vitamin D deficient in winter and 59.8% in summer. The highest proportion of vitamin D deficient individuals was found in the group representing the postmenopausal women not taking vitamin D supplements.

Postmenopausal osteoporosis and tooth loss.

OBJECTIVE: The aim of this study was to determine relation between tooth loss and general body bone mineral density in postmenopausal female who were seeking for prosthetic treatment. MATERIAL AND METHODS: There were included 79 women in this study (age from 49-81 years, mean age 62.9 years) with partial tooth loss. For all patients bone mineral density measurements for lumbar spine and both femoral necks by dual energy X-ray absorptiometry (Lunar DEXA DPX-NT, GE Medical Systems) were performed. Based on DEXA results patients were divided into 3 groups: normal bone density (T-score ≥-1.0), osteopenia (T-score from -1.0 till -2.5) and osteoporosis (T-score ≤-2.5). Dental investigation was performed to detect existing teeth. ANOVA analysis of variance was used to determine relationship between different variables by group. To test correlation between different values Pearson correlation was used. RESULTS: The number of teeth in different bone mineral density groups is almost similar. There are no statistically significant differences between groups according the number of the all teeth present and according the number of teeth in maxilla and mandible. There is no significant correlation between the number of the teeth and DEXA readings, except there is weak correlation between the number of maxillary posterior teeth and bone mineral density in femoral neck. CONCLUSION: There is no correlation between number of the teeth and general bone mineral density.