Prevalence of Vitamin D inadequacy among postmenopausal North American women receiving osteoporosis therapy

J Clin Endocrinol Metab. 2005 Jun;90(6):3215-24. doi: 10.1210/jc.2004-2364. Epub 2005 Mar 29.


Purpose: To evaluate serum 25-hydroxyvitamin D [25(OH)D] concentrations and factors related to vitamin D inadequacy in postmenopausal North American women receiving therapy to treat or prevent osteoporosis.

Methods: Serum 25(OH)D and PTH were obtained in 1536 community-dwelling women between November 2003 and March 2004. Multivariate logistic regression was used to assess risk factors for suboptimal (<30 ng/ml) 25(OH)D.

Results: Ninety-two percent of study subjects were Caucasian, with a mean age of 71 yr. Thirty-five percent resided at or above latitude 42 degrees north, and 24% resided less than 35 degrees north. Mean (sd) serum 25(OH)D was 30.4 (13.2) ng/ml: serum 25(OH)D was less than 20 ng/ml in 18%; less than 25 ng/ml in 36%; and less than 30 ng/ml in 52%. Prevalence of suboptimal 25(OH)D was significantly higher in subjects who took less than 400 vs. 400 IU/d or more vitamin D. There was a significant negative correlation between serum PTH concentrations and 25(OH)D. Risk factors related to vitamin D inadequacy included age, race, body mass index, medications known to affect vitamin D metabolism, vitamin D supplementation, exercise, education, and physician counseling regarding vitamin D.

Conclusions: More than half of North American women receiving therapy to treat or prevent osteoporosis have vitamin D inadequacy, underscoring the need for improved physician and public education regarding optimization of vitamin D status in this population.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Accidental Falls / statistics & numerical data
  • Activities of Daily Living
  • Calcifediol / blood
  • Calcifediol / deficiency
  • Demography
  • Educational Status
  • Female
  • Fractures, Bone / epidemiology
  • Health Status
  • Humans
  • Income
  • Middle Aged
  • North America / epidemiology
  • Osteoporosis, Postmenopausal / drug therapy*
  • Osteoporosis, Postmenopausal / prevention & control
  • Parathyroid Hormone / blood
  • Prevalence
  • Regression Analysis
  • Risk Factors
  • Vitamin D Deficiency / epidemiology*


  • Parathyroid Hormone
  • Calcifediol