Title | Seasonal variation in 25-hydroxyvitamin D concentrations in the cardiovascular health study. |
Publication Type | Journal Article |
Year of Publication | 2011 |
Authors | Shoben, AB, Kestenbaum, B, Levin, G, Hoofnagle, AN, Psaty, BM, Siscovick, DS, de Boer, IH |
Journal | Am J Epidemiol |
Volume | 174 |
Issue | 12 |
Pagination | 1363-72 |
Date Published | 2011 Dec 15 |
ISSN | 1476-6256 |
Keywords | Aged, Biomarkers, Continental Population Groups, Exercise, Female, Humans, Male, Residence Characteristics, Seasons, Sex Factors, Vitamin D |
Abstract | <p>Low circulating concentrations of 25-hydroxyvitamin D (25(OH)D) are associated with adverse health outcomes in diverse populations. However, 25(OH)D concentrations vary seasonally with varying exposure to sunlight, so single measurements may poorly reflect long-term 25(OH)D exposure. The authors investigated cyclical trends in average serum 25(OH)D concentrations among 2,298 individuals enrolled in the Cardiovascular Health Study of community-based older adults (1992-1993). A sinusoidal model closely approximated observed 25(OH)D concentrations and fit the data significantly better than did a mean model (P < 0.0001). The mean annual 25(OH)D concentration was 25.1 ng/mL (95% confidence interval: 24.7, 25.5), and the mean peak-trough difference was 9.6 ng/mL (95% confidence interval: 8.5, 10.7). Male sex, higher latitude of study site, and greater physical activity levels were associated with larger peak-trough difference in 25(OH)D concentration (each P < 0.05). Serum concentrations of intact parathyroid hormone and bone-specific alkaline phosphatase also varied in a sinusoidal fashion (P < 0.0001), inversely to 25(OH)D. In conclusion, serum 25(OH)D varies in a sinusoidal manner, with large seasonal differences relative to mean concentration and laboratory evidence of biologic sequelae. Single 25(OH)D measurements might not capture overall vitamin D status, and the extent of misclassification could vary by demographic and behavioral factors. Accounting for collection time may reduce bias in research studies and improve decision-making in clinical care.</p> |
DOI | 10.1093/aje/kwr258 |
Alternate Journal | Am. J. Epidemiol. |
PubMed ID | 22112344 |
PubMed Central ID | PMC3276302 |
Grant List | M01-RR00425 / RR / NCRR NIH HHS / United States R01AG027002 / AG / NIA NIH HHS / United States R01 DK088762 / DK / NIDDK NIH HHS / United States N01-HC-85085 / HC / NHLBI NIH HHS / United States U01 HL080295 / HL / NHLBI NIH HHS / United States N01-HC-85081 / HC / NHLBI NIH HHS / United States R01HL096875 / HL / NHLBI NIH HHS / United States N01 HC015103 / HC / NHLBI NIH HHS / United States R01 HL087652 / HL / NHLBI NIH HHS / United States N01HC55222 / HL / NHLBI NIH HHS / United States N01-HC-85086 / HC / NHLBI NIH HHS / United States N01HC85086 / HL / NHLBI NIH HHS / United States N01-HC-85082 / HC / NHLBI NIH HHS / United States P30 DK063491 / DK / NIDDK NIH HHS / United States N01 HC-55222 / HC / NHLBI NIH HHS / United States N01-HC-85083 / HC / NHLBI NIH HHS / United States N01-HC-75150 / HC / NHLBI NIH HHS / United States N01-HC-85080 / HC / NHLBI NIH HHS / United States R01 HL084443 / HL / NHLBI NIH HHS / United States R01 AG027002 / AG / NIA NIH HHS / United States M01 RR000425 / RR / NCRR NIH HHS / United States N01HC75150 / HL / NHLBI NIH HHS / United States KL2 RR025015 / RR / NCRR NIH HHS / United States DK063491 / DK / NIDDK NIH HHS / United States N01-HC-85079 / HC / NHLBI NIH HHS / United States N01-HC-85239 / HC / NHLBI NIH HHS / United States N01HC85079 / HL / NHLBI NIH HHS / United States N01 HC045133 / HC / NHLBI NIH HHS / United States R01 HL096875 / HL / NHLBI NIH HHS / United States N01 HC035129 / HC / NHLBI NIH HHS / United States N01-HC-85084 / HC / NHLBI NIH HHS / United States 1KL2RR025015 / RR / NCRR NIH HHS / United States |