Investigating the patterns and determinants of seasonal variation in vitamin D status in Australian adults: the Seasonal D Cohort Study

BMC Public Health. 2016 Aug 26;16(1):892. doi: 10.1186/s12889-016-3582-z.

Abstract

Background: Vitamin D status generally varies seasonally with changing solar UVB radiation, time in the sun, amount of skin exposed, and, possibly, diet. The Seasonal D Study was designed to quantify the amplitude and phase of seasonal variation in the serum concentration of 25-hydroxyvitamin D, (25OH)D)) and identify the determinants of the amplitude and phase and those of inter-individual variability in seasonal pattern.

Methods: The Seasonal D Study collected data 2-monthly for 12 months, including demographics, personal sun exposure using a diary and polysulphone dosimeters over 7 days, and blood for serum 25(OH)D concentration. The study recruited 333 adults aged 18-79 years living in Canberra (35°S, n = 168) and Brisbane (27°South, n = 165), Australia.

Discussion: We report the study design and cohort description for the Seasonal D Study. The study has collected a wealth of data to examine inter- and intra-individual seasonal variation in vitamin D status and serum 25(OH)D levels in Australian adults.

Keywords: Adult; Australia; Cohort; Determinants; Season; Vitamin D.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Australia / epidemiology
  • Climate*
  • Cohort Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Seasons*
  • Skin
  • Sunlight*
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology
  • Vitamin D Deficiency / etiology*
  • Young Adult

Substances

  • Vitamin D
  • 25-hydroxyvitamin D