Does my child need a vitamin D supplement?

What the evidence says

If your baby is breastfed (even partially), Canadian guidelines recommend a daily vitamin D supplement of 400 IU starting right from birth, continuing at least until their diet regularly includes enough vitamin D from other foods or they turn one. If your baby has extra risk factors -- darker skin, limited sun exposure, living in a northern community, or a mother who was vitamin D deficient -- the recommended amount doubles to 800 IU per day, year-round.

Formula-fed babies usually don't need a supplement, since infant formula in Canada already has vitamin D added, as long as they're drinking a normal amount of formula.

Once children are past infancy, there isn't strong Canadian guidance requiring a routine supplement if they're getting vitamin D through fortified cow's milk, some plant-based beverages, or foods like fatty fish and egg yolks. However, research shows many Canadian children still fall short of ideal vitamin D levels, so if your child drinks little fortified milk, has darker skin, gets little sun exposure, or has other risk factors, it's worth asking your doctor or dietitian whether a supplement makes sense for them.

If you're pregnant or breastfeeding yourself, it's also worth asking your care provider whether a maternal vitamin D supplement (up to 2000 IU/day) is right for you, since your vitamin D status affects your baby's.