Individual participant data (IPD)-level meta-analysis of randomised controlled trials with vitamin D-fortified foods to estimate Dietary Reference Values for vitamin D.
CONTEXT AND PURPOSE: Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D
METHODS: IPD analysis using data from 1429 participants (ages 2-89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models.
RESULTS: Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI).
CONCLUSIONS: IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D < 30 nmol/L) in the general population.
European Journal of Nutrition
DOI of Published Version
Cashman, Kevin D; Kiely, Mairead E; Andersen, Rikke; Grønborg, Ida M; Madsen, Katja H; Nissen, Janna; Tetens, Inge; Tripkovic, Laura; Lanham-New, Susan A; Toxqui, Laura; Vaquero, M Pilar; Trautvetter, Ulrike; Jahreis, Gerhard; Mistry, Vikram V.; Specker, Bonny; Hower, Jürgen; Knoll, Anette; Wagner, Dennis; Vieth, Reinhold; Öhlund, Inger; Karlsland Åkeson, Pia; Brett, Neil R; Weiler, Hope A; and Ritz, Christian, "Individual participant data (IPD)-level meta-analysis of randomised controlled trials with vitamin D-fortified foods to estimate Dietary Reference Values for vitamin D." (2020). Ethel Austin Martin Program Publications. 117.