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

J Nutr Health Aging. 2011 May;15(5):349-54. doi: 10.1007/s12603-010-0287-3.

Abstract

Background: Vitamin D insufficiency is common in elderly adults, and leads to secondary hyperparathyroidism, bone loss, muscle weakness, and osteoporotic fractures.

Objective: To evaluate the relation between vitamin D nutritional status and muscle function and muscle strength in women aged over 65 years.

Methods: Fifty-four postmenopausal women from Buenos Aires (latitude 34° 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.

Results: 25OHD levels ≥20 ng/ml were found to be associated with better lower extremity muscle function and strength. Forty- six % of participants had 25OHD levels ≥20 ng/ml. Women with 25OHD levels ≥20 ng/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).

Conclusion: 25OHD levels ≥20 ng/ml are needed for a better muscle function and strength. Assessing vitamin D nutritional status in adults aged ≥ 65 years would allow correcting hypovitaminosis D and improve muscle function and strength.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Female
  • Geriatric Assessment
  • Humans
  • Lower Extremity / physiology*
  • Movement
  • Muscle Strength / physiology*
  • Muscle Weakness / blood
  • Muscle Weakness / prevention & control*
  • Muscle, Skeletal / physiology*
  • Muscle, Skeletal / physiopathology
  • Nutritional Status*
  • Parathyroid Hormone / blood
  • Physical Fitness
  • Postmenopause
  • Postural Balance
  • Prevalence
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology
  • Vitamin D Deficiency / physiopathology*
  • Walking

Substances

  • Parathyroid Hormone
  • Vitamin D
  • 25-hydroxyvitamin D