The vitamin D status of the US population from 1988 to 2010 using standardized serum concentrations of 25-hydroxyvitamin D shows recent modest increases

Am J Clin Nutr. 2016 Aug;104(2):454-61. doi: 10.3945/ajcn.115.127985. Epub 2016 Jul 6.

Abstract

Background: Temporal trends in the US population's vitamin D status have been uncertain because of nonstandardized serum 25-hydroxyvitamin D [25(OH)D] measurements.

Objective: To accurately assess vitamin D status trends among those aged ≥12 y, we used data from the cross-sectional NHANESs.

Design: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring 25(OH)D (sum of 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3), calibrated to standard reference materials, was used to predict LC-MS/MS-equivalent concentrations from radioimmunoassay data (1988-2006 surveys; n = 38,700) and to measure LC-MS/MS concentrations (2007-2010 surveys; n = 12,446). Weighted arithmetic means and the prevalence of 25(OH)D above or below cutoff concentrations were calculated to evaluate long-term trends.

Results: Overall, mean predicted 25(OH)D showed no time trend from 1988 to 2006, but during 2007-2010 the mean measured 25(OH)D was 5-6 nmol/L higher. Those groups who showed the largest 25(OH)D increases (7-11 nmol/L) were older, female, non-Hispanic white, and vitamin D supplement users. During 1988-2010, the proportions of persons with 25(OH)D <40 nmol/L were 14-18% (overall), 46-60% (non-Hispanic blacks), 21-28% (Mexican Americans), and 6-10% (non-Hispanic whites).

Conclusions: An accurate method for measuring 25(OH)D showed stable mean concentrations in the US population (1988-2006) and recent modest increases (2007-2010). Although it is unclear to what extent supplement usage compared with different laboratory methods explain the increases in 25(OH)D, the use of higher vitamin D supplement dosages coincided with the increase. Marked race-ethnic differences in 25(OH)D concentrations were apparent. These data provide the first standardized information about temporal trends in the vitamin D status of the US population.

Keywords: NHANES; standardization; supplements; survey; trend; vitamin D.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • African Americans
  • Aged
  • Child
  • Dietary Supplements
  • European Continental Ancestry Group
  • Female
  • Hispanic Americans
  • Humans
  • Male
  • Middle Aged
  • Nutrition Surveys
  • Nutritional Status* / ethnology
  • Prevalence
  • United States / epidemiology
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood*
  • Vitamin D / therapeutic use
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / prevention & control
  • Vitamins / blood*
  • Vitamins / therapeutic use
  • Young Adult

Substances

  • Vitamins
  • Vitamin D
  • 25-hydroxyvitamin D