Vitamin D Deficiency and Its Influence on Bone Metabolism and Density in a Brazilian Population of Healthy Men

J Clin Densitom. 2018 Jan-Mar;21(1):91-97. doi: 10.1016/j.jocd.2017.01.008. Epub 2017 Feb 21.

Abstract

Vitamin D supplementation is universal for postmenopausal women, but not for elderly men, in whom osteoporosis is also commonly neglected. This study aimed to evaluate vitamin D deficiency and its association with secondary hyperparathyroidism, bone resorption, and bone density in Brazilian men. A total of 120 men, 20-93 years, were evaluated for serum calcium, phosphorus, creatinine, 25-hydroxyvitamin D (25(OH)D), parathyroid hormone, biochemical markers of bone resorption (carboxy-terminal telopeptide, carboxy-terminal peptide of type I collagen), and bone mineral density (dual-energy X-ray absorptiometry). Glomerular filtration rate (GFR) below 30 mL/min/1.73 m2, chronic diseases, and medications affecting bone were the exclusion criteria. No participant reported previous low-impact fractures. In the overall population, 25(OH)D levels were below 30 ng/mL in 46.7%, and below 20 ng/mL in 27.6%. Among the 93 patients 50 years and older, 28 had osteoporosis. In those 70 years and older, the prevalence of vitamin D deficiency (42.1%), secondary hyperparathyroidism (46.4%), high bone resorption (39.6%), decreased GFR (39.2%), and osteoporosis (41.4%) was significantly higher than in the younger subjects (p < 0.005 for all comparisons). Serum parathyroid hormone increased with aging and declining GFR, but was not significantly associated with 25(OH)D or bone mineral density. There was a clear contribution of vitamin D deficiency to increased bone resorption and osteoporosis. Binary logistic regression model considering age, 25(OH)D, and bone resorption identified age ≥70 years as the main determinant of osteoporosis. Our data demonstrate a high prevalence of vitamin D deficiency in a male population living in Rio de Janeiro, and emphasize its participation on the pathogenesis of age-related bone loss. (Vitamin D deficiency and osteoporosis are common in elderly Brazilian men.).

Keywords: Bone resorption; hyperparathyroidism; men; osteoporosis; vitamin D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Bone Density*
  • Bone Resorption / epidemiology*
  • Bone and Bones / metabolism
  • Brazil / epidemiology
  • Calcium / blood
  • Creatinine / blood
  • Cross-Sectional Studies
  • Glomerular Filtration Rate
  • Healthy Volunteers
  • Humans
  • Hyperparathyroidism, Secondary / epidemiology*
  • Hyperparathyroidism, Secondary / physiopathology
  • Male
  • Middle Aged
  • Osteoporosis / diagnostic imaging
  • Osteoporosis / epidemiology*
  • Parathyroid Hormone / blood
  • Phosphorus / blood
  • Prevalence
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / physiopathology*
  • Young Adult

Substances

  • Parathyroid Hormone
  • Vitamin D
  • Phosphorus
  • 25-hydroxyvitamin D
  • Creatinine
  • Calcium