The vitamin D status and its effects on life quality among the elderly in Jinan, China.

A challenge for researchers is that vitamin D has many functions in the body, and vitamin D status across the world is not optimistic. There was little data regarding insufficient vitamin D status and its adverse effect on health of elderly Chinese people. So we selected 686 subjects (310 men and 376 women) aged 60-89 years to explore the correlation between vitamin D status and their life quality in a community-based osteoporosis prevention study at Qianfoshan Hospital of Shandong University from 2009 to 2010. All subjects were divided into three groups: vitamin D adequacy [serum 25(OH)D ≧ 75 nmol/L], hypovitaminosis D (50-74.9 nmol/L), and vitamin D insufficiency (<50 nmol/L). Participants were requested to complete SF-36 health survey. The regression models were used to evaluate respectively the association between 25(OH)D levels and parameters of SF-36. As a result, serum 25(OH)D levels were 58.60 nmol/L in male [95% confidence interval (95% CI): 56.7-60.5 nmol/L] and 54.17 nmol/L in female (95% CI: 52.8-55.8 nmol/L). Vitamin D adequacy was in 19.4% of male and 14.4% of female. With aging, proportions of insufficient vitamin D increased significantly in male (P=0.004), and in female (P<0.001). The elderly with hypovitaminosis D got lower scores than that with vitamin D adequacy (almost P<0.01). Regression analysis showed that vitamin D appeared a positive association with parameters of SF-36 (almost P<0.001). In conclusion, vitamin D status in the elderly was severely inadequate, which decreased their life quality and cause adverse effect on their health.