Study description
VIDI study was a randomized, double-blinded, 2-year clinical trial of daily vitamin D3 supplementation of 10 µg (400 IU) or 30 µg (1200 IU) administered to 987 infants.

Between January 2013 and June 2014, families were recruited at Kätilöopisto Helsinki Maternity Hospital, Helsinki, Finland. The primary outcomes were bone strength and incidence of parent-reported infections. Secondary outcomes included child growth and development, and incidence of asthma and allergies. Main results have been published (see publications).

We have completed a VIDI follow-up study (VIDI2) when the children were 6 to 7 years of age during 2019-2021. Main aim of the follow-up study is to investigate long-term health consequences of early childhood vitamin D intervention. Data processing and analyzing is currently ongoing.

Study is carried out by HUS Helsinki University Hospital together with University of Helsinki, in a collaboration with Folkhälsan Research Center and Karolinska Institutet.