Administration of Vitamin D to babies

What are the pros and cons of Vitamin D supplementation for all babies?

Some people oppose this universal recommendation, arguing that it should apply only to babies whose mothers are at risk of having low vitamin D reserves. This risk is more common in populations with limited sun exposure, such as Nordic populations or individuals from certain religious communities (e.g., Orthodox groups). If a breastfeeding mother has low levels of vitamin D, the baby may not receive enough through breast milk alone. Additionally, because breast milk is not a sufficient source of vitamin D and formula is typically fortified with it, some argue that supplementation should be recommended only for breastfed babies.
This also raises another question: which is better—breastfeeding or formula? (Read here).
On the other hand, a strict recommendation to give vitamin D to all babies does not differentiate between formula-fed and breastfed infants who already have normal levels of vitamin D. As a result, these babies would also receive a supplement. However, since it’s not practical to identify which babies have adequate levels (we’re not going to start drawing blood samples from all newborns to test for vitamin D), and because the supplement has no known side effects, I believe it’s a reasonable recommendation.

What is the dose of vitamin D, and is there a preference for one brand over another?

The recommended daily amount of vitamin D₃ for babies is 400 international units (IU), regardless of whether the baby is full-term or preterm. There are vitamin D preparations in which one drop contains the full daily dose, and others where two drops are needed (each containing 200 IU).
– There is no significant advantage or disadvantage between different brands that manufacture vitamin D.
– There are no known side effects associated with the recommended dose.
Parents can choose any time of day to give the supplement. However, since routine is important (otherwise it’s easy to forget), it’s best to choose a specific hour and stick to it each day. Vitamin D can also be given alongside iron supplements (which are usually started at around 4 months of age — read here). I recommend parents give both supplements at the same time each day to avoid missing a dose.
There is no need for special blood tests or a doctor’s order to stop vitamin D supplementation. Simply stop at one year of age—consider it a little birthday gift for your baby!