Why is vitamin D supplementation recommended for breastfed infants and how much?

• A. Vitamin D supplementation is always unnecessary.
• B. Supplement with 1000 IU weekly.
• C. Breast milk may be deficient in vitamin D; supplement with 400 IU daily starting early after birth.
• D. Only formula-fed babies require vitamin D.

Answer: (C)

Vitamin D is essential for bone development and calcium metabolism in infants, and breast milk often provides only small amounts of it. Because babies rely on what they receive from early feeding, a daily supplement helps ensure they get enough vitamin D, reducing the risk of deficiency and rickets. The widely endorsed amount is 400 international units per day, starting soon after birth and continuing throughout infancy as long as the infant remains breastfed or consumes less than about a liter of vitamin D–fortified formula daily. This daily dose aligns with pediatric guidelines and is preferred over seeing a large weekly dose, which doesn’t provide consistent daily intake. The idea that supplementation isn’t needed or that only formula-fed babies need it isn’t accurate, since formula provides vitamin D while breastfed babies still need a daily supplement to reach the recommended amount.