Vitamin D status and parathyroid hormone levels in relation to bone mineral density in apparently healthy Syrian adults.

UNLABELLED: Vitamin D deficiency was highly prevalent in this study. More than half of the participants with vitamin D level less than 5 ng/mL had secondary hyperparathyroidism, which implicated a major bone health concern. After adjustment for potential predictors, parathyroid hormone (PTH) explained about 3 % of the variance in total hip bone mineral density (BMD). PURPOSE: Bone mineral density (BMD) is known to be influenced by serum 25-hydroxyvitamin D (25OHD) and intact parathyroid hormone (PTH) levels. The relationship between 25OHD and PTH with BMD has not been well documented in Syrian adults. We aimed to determine how differences in serum 25OHD and PTH levels impacted hip and lumbar spine BMD among apparently healthy Syrian adults. METHODS: 25OHD and PTH were measured in 156 participants aged 18-53 years from Damascus and its surroundings. Lumbar spine and hip BMD measurements were measured by dual-energy X-ray absorptiometry using Hologic Discovery Wi densitometer. Multivariate regression models were used to investigate the relationships between 25OHD, PTH, and BMD. RESULTS: All participants, except one male, had 25OHD <30 ng/mL (<75 nmol/L), and 89.1 % of them had 25OHD levels less than 20 ng/mL (50 nmol/L). Secondary hyperparathyroidism was significantly more prevalent in the lowest 25OHD quartile compared to that in the highest quartile (59 vs. 10.3 %, p < 0.0001). Mean bone mineral density at all sites in our participants was lower when compared to that of their Caucasian counterparts in Europe and North America. No significant correlation was found between 25OHD and BMD either at hip or at lumbar spine. In the multivariate analyses, after adjustment for potential predictors, PTH explained about 3 % of the variation in total hip BMD. CONCLUSIONS: Low BMD was relatively frequent at all measured sites. PTH, but not 25OHD, was a predictor for total hip BMD in a young population.

Relationship between 25-hydroxyvitamin D concentrations, serum calcium, and parathyroid hormone in apparently healthy Syrian people.

UNLABELLED: Vitamin D deficiency (25-hydroxyvitamin D (25OHD) <25 nmol/L) was common in a convenience sample of apparently healthy Syrian adults. Female gender, season, and concealing clothing were independent predictors of vitamin D deficiency. Community-based research is needed to identify vulnerable subgroups and inform public health actions. PURPOSE: Optimal vitamin D status for bone health has been inferred from the determination of serum 25OHD levels below which there is an increase in serum parathyroid hormone (PTH). Studies worldwide showed high prevalence of hypovitaminosis D even in sunny countries. There is little evidence about its prevalence among Syrian adult population. We aimed to assess the serum levels of 25OHD and factors related to vitamin D inadequacy and its relation to serum PTH and calcium among apparently healthy adults. METHODS: Serum 25OHD and PTH measurements were obtained from 372 subjects aged 18-62 years living in Damascus and its surroundings, between April 2011 and March 2013. Binary logistic regression was used to assess risk factors for hypovitaminosis D. RESULTS: The mean (standard deviation (SD)) 25OHD level was 24.7 (16.9) nmol/L [9.8 (6.7) ng/mL] and was higher in men than women (p < 0.001). Levels <25, <50, and <75 nmol/L were detected in 61, 90.1, and 99.2 % of the participants, respectively. Season influenced vitamin D status in men but not in women (p < 0.001). Female gender and wearing the veil (hijab) were independent predictors of vitamin D deficiency (25OHD <25 nmol/L). PTH was significantly higher below this threshold (p < 0.001). Serum 25OHD <25 nmol/L, sex, and age ≥ 35 years were statistically significant factors for PTH elevation. CONCLUSIONS: Vitamin D deficiency was highly prevalent in our sample. Further research is needed to identify population groups vulnerable for hypovitaminosis D and specify its predictors and inform the necessary public health measures.