TY - JOUR

T1 - Assessing Health Consequences of Vitamin D Fortification Utilizing a Societal Experiment Design

T2 - Methodological Lessons Learned from the D-Tect Project

AU - Handel, Mina Nicole

AU - Jacobsen, Ramune

AU - Thorsteinsdottir, Fanney

AU - Keller, Amelie Cleo

AU - Stougaard, Maria

AU - Jensen, Camilla Bjørn

AU - Moos, Caroline

AU - Duus, Katrine Sidenius

AU - Jensen, Allan

AU - Kesmodel, Ulrik Schioler

AU - Abrahamsen, Bo

AU - Heitmann, Berit Lilienthal

PY - 2021

Y1 - 2021

N2 - By utilizing historical changes in Danish legislation related to mandatory vitamin D fortification of margarine, which was implemented in the mid 1930s and abruptly abandoned in June 1985, the studies in the D-tect project investigated the effects of vitamin D on health outcomes in individuals, who during gestation were exposed or unexposed to extra vitamin D from fortified margarine. This paper reviews and narratively summarizes the analytic approaches alongside the results of the societal fortification experiment studies from the D-tect project and addresses the challenges in designing societal experiment studies and evaluating their results. The latter are discussed as lessons learned that may be useful for designers of similar studies, expected to be extensively utilized while researching the health consequences of the COVID-19 pandemic by comparing individuals born before and after the epidemic. In the D-tect project, 16 articles based on the societal fortification experiment were published analyzing 10 different outcomes and using different statistical approaches. Lessons learned included the detail of the analysis of the historical information on the exposure, availability and validity of the outcome data, variety of analytical approaches, and specifics concerning vitamin D effect evaluation, such as consideration of the influence of sunshine or season. In conclusion, the D-tect project clearly demonstrated the cost-effectiveness and research potential of natural- or societal-experiment-based studies.

AB - By utilizing historical changes in Danish legislation related to mandatory vitamin D fortification of margarine, which was implemented in the mid 1930s and abruptly abandoned in June 1985, the studies in the D-tect project investigated the effects of vitamin D on health outcomes in individuals, who during gestation were exposed or unexposed to extra vitamin D from fortified margarine. This paper reviews and narratively summarizes the analytic approaches alongside the results of the societal fortification experiment studies from the D-tect project and addresses the challenges in designing societal experiment studies and evaluating their results. The latter are discussed as lessons learned that may be useful for designers of similar studies, expected to be extensively utilized while researching the health consequences of the COVID-19 pandemic by comparing individuals born before and after the epidemic. In the D-tect project, 16 articles based on the societal fortification experiment were published analyzing 10 different outcomes and using different statistical approaches. Lessons learned included the detail of the analysis of the historical information on the exposure, availability and validity of the outcome data, variety of analytical approaches, and specifics concerning vitamin D effect evaluation, such as consideration of the influence of sunshine or season. In conclusion, the D-tect project clearly demonstrated the cost-effectiveness and research potential of natural- or societal-experiment-based studies.

KW - vitamin D

KW - pregnancy

KW - chronic diseases

KW - semi-ecological study

KW - FORTIFIED MARGARINE

KW - PRENATAL EXPOSURE

KW - PUBLIC-HEALTH

KW - BODY-SIZE

KW - RISK

KW - FETAL

KW - MILK

KW - REGISTERS

KW - LIFE

U2 - 10.3390/ijerph18158136

DO - 10.3390/ijerph18158136

M3 - Review

C2 - 34360427

VL - 18

JO - International Journal of Environmental Research and Public Health

JF - International Journal of Environmental Research and Public Health

SN - 1661-7827

IS - 15

M1 - 8136

ER -