Objective To determine the relationship between serum levels of 25(OH)D and 1,25(OH)2 D and the hand-grip strength and balance ability of women in Sichuan, China. Methods A cross-sectional study on a representative sample of 1 095 women aged 29-95 yr. in Sichuan Province was undertaken. Their hand-grip strength and balance ability were assessed using a hand-held dynamometer and the short physical performance battery (SPPB), respectively. The participants were divided into four groups according to the level of serum 25(OH)D: sufficient (>75 nmol/L), insufficient (51-75 nmol/L), deficiency (25-50 nmol/L), and serious deficiency (<25 nmol/L). General liner models were established to compare the differences of the four groups in balance ability. Logistic regression models were established to examine the associations of serum 25(OH)D and 1,25(OH)2 D withhand-grip strength and physical performance. Results About 70.9% of the participants had vitamin D deficiency.
