Should measurement of vitamin D and treatment of vitamin D insufficiency be routine in New Zealand?

N Z Med J. 2012 Feb 10;125(1349):83-91.

Abstract

Epidemiological studies have reported associations between lower vitamin D levels and a great variety of diseases, prompting calls for widespread treatment of individuals with low vitamin D levels. Most of New Zealand's population have vitamin D levels for at least part of the year that are considered insufficient (25-hydroxyvitamin D <50-80 nmol/L). However, evidence for benefits of vitamin D supplementation in such populations is controversial and there is some evidence of harmful effects. Until adequately powered, randomised, controlled trials of vitamin D supplementation demonstrate safe improvements in health, clinicians should not focus on detecting/treating individuals with vitamin D insufficiency, instead treating those at high risk of vitamin D deficiency (25-hydroxyvitamin D <25 nmol/L), such as the frail elderly, and those with specific clinical indications. Treatment for such individuals does not require vitamin D measurements. Requests for vitamin D measurements in Auckland have nearly quadrupled in the past decade, from 8500 in the year 2000 to 32,800 in 2010, with substantial increases in cost. Vitamin D measurement is often inaccurate and imprecise, and the vast majority of tests performed currently do not reveal vitamin D deficiency. Therefore, a move away from routine vitamin D measurements seems sensible, though they are still indicated when investigating suspected metabolic bone disease or hypocalcaemia.

MeSH terms

  • Dietary Supplements* / adverse effects
  • Health Care Costs
  • Humans
  • Mass Screening
  • Meta-Analysis as Topic
  • New Zealand
  • Observation
  • Reproducibility of Results
  • Vitamin D / adverse effects
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D / therapeutic use*
  • Vitamin D Deficiency* / diagnosis
  • Vitamin D Deficiency* / drug therapy
  • Vitamin D Deficiency* / economics
  • Vitamins / adverse effects
  • Vitamins / therapeutic use*

Substances

  • Vitamins
  • Vitamin D
  • 25-hydroxyvitamin D