2400 IU of vitamin D needed to get most Northern adults above 20 ng – June 2020

Individual Participant Data (IPD)-level Meta-Analysis of Randomised Controlled Trials With Vitamin D-fortified Foods to Estimate Dietary Reference Values for Vitamin D

Eur J Nutr. 2020 Jun 15. doi: 10.1007/s00394-020-02298-x.
Kevin D Cashman 1 2, Mairead E Kiely 3, Rikke Andersen 4, Ida M Grønborg 4, Katja H Madsen 4, Janna Nissen 4, Inge Tetens 4 5, Laura Tripkovic 6, Susan A Lanham-New 6, Laura Toxqui 7, M Pilar Vaquero 7, Ulrike Trautvetter 8, Gerhard Jahreis 8, Vikram V Mistry 9, Bonny L Specker 10, Jürgen Hower 11, Anette Knoll 12, Dennis Wagner 13, Reinhold Vieth 13 14, Inger Öhlund 15, Pia Karlsland Åkeson 16, Neil R Brett 17, Hope A Weiler 17, Christian Ritz 5

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IUs needed to get 97.5% of Northern adults to above 20 ng

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 D3-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for 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.