Randomised placebo controlled study of vitamin D during pregnancy and infancy

This study is testing two different doses of daily vitamin D supplements — given during pregnancy and continued in early infancy — to find the safest and most effective amount to prevent vitamin D deficiency in New Zealand babies. Vitamin D deficiency is common in New Zealand and can affect bone health, immune function, and the risk of infections and allergies in young children. The goal is to provide recommendations to the Ministry of Health about whether pregnant women and infants should receive vitamin D supplements. You may be eligible if: - You are pregnant and planning to deliver at Middlemore Hospital - You are either a public patient or your midwife (lead maternity caregiver) is part of South Auckland Maternity Care Limited (SAMCL) You may NOT be eligible if: - You are already taking more than 200 IU of vitamin D per day - You have a history of kidney stones or high calcium levels in your blood - You have a serious complication of pregnancy at the time of enrolment Talk to your doctor about whether this trial might be right for you.