Effect of vitamin D nutritional status on muscle function and strength in healthy women aged over sixty-five years

Vitamin D insufficiency is common in elderly adults, and leads to secondary hyperparathyroidism, bone loss, muscle weakness, and osteoporotic fractures. To evaluate the relation between vitamin D nutritional status and muscle function and muscle strength in women aged over 65 years. Fifty-four postmenopausal women from Buenos Aires (latitude 34A degrees S), average age (X +/- DS) 71 +/- 4, were included in the study. Determinations of serum calcium, phosphate, 25 hydroxyvitamin D (25OHD), intact parathormone (iPTH) and calciuria / creatininuria ratio in 24-hour urine samples were performed. Muscle function was assessed by means of walking-speed test, standing balance, and sit-to-stand tests. lower extremity muscle strength was determined using a manual dynamometer. 25OHD levels a parts per thousand yen20ng/ml were found to be associated with better lower extremity muscle function and strength. Forty- six % of participants had 25oHD levels a parts per thousand yen20ng/ml. Women with 25OHD levels a parts per thousand yen20ng/ml scored higher on the muscle function tests (11.2 +/- 0.9 vs.10.0 +/- 2.1; p < 0.003) and had stronger knee extensor (13.4 +/- 2.7 vs.11.6 +/- 2.5 Kg.; p < 0.03) and hip abductor (8.3 +/- 2.7 vs. 7.3 +/- 3.1 Kg; p < 0.04) muscles; strength of their hip flexors tended to be higher but did not reach significantly different values (17.0 +/- 3.3 vs. 15.4 +/- 2.8 Kg.; 0.1 > p > 0.05). Negative correlation was observed between iPtH and muscle function (r= -0.436; p < 0.02). 25OHD levels a parts per thousand yen20ng/ml are needed for a better muscle function and strength. assessing vitamin D nutritional status in adults aged a parts per thousand yen 65 years would allow correcting hypovitaminosis D and improve muscle function and strength.