The First 1000 Days: Vitamin D for premature babies


Vitamin D for premature babies is an important medical intervention.

Babies born prematurely (before 37 weeks) are recommended to be given 200 to 400IU of vitamin D daily while in hospital and after being discharged. This is to prevent the development of vitamin D deficiency causing rickets (a disease that leads to weakened and soft bones, bone deformity and the appearance of bowed legs).  Some preterm babies are also given calcium and phosphorus to assist in normal bone formation and growth.

Why do preterm babies need vitamin D?

Calcium is deposited into the baby’s bones during the third trimester, so babies born early have less bone mineral density and have different bone mineral requirements compared to full-term newborns. Vitamin D is needed for the absorption and transfer of calcium from the digestive tract into the bones, where mineralization takes place.

At birth, babies have a limited amount of vitamin D stores passed on from the mother during pregnancy. Many countries recommended vitamin D3 baby supplements to all newborns, especially babies that are exclusively breastfed. This is because breastmilk naturally contains low levels of vitamin D, and with the addition of many mothers having low vitamin D levels, the risk of vitamin D deficiency in newborns is high. Premature babies have less time in the womb to acquire maternal vitamin D stores, placing preterm babies at an increased risk of vitamin D deficiency.

What do vitamin D drops do for babies?

Along with preventing rickets, vitamin D for newborns (particularly those born before 37 weeks) is needed for normal immune system function and to prevent infections and autoimmune diseases (an autoimmune disease is a condition in which the immune system mistakenly attacks its own body cells). Adequate amounts of vitamin D during infancy and childhood may also reduce the risk of osteoporosis in later life.

How long should vitamin D drops for babies be taken?

For babies that are at an increased risk of vitamin D deficiency, it is recommended to continue supplementation until sufficient nutrients can be obtained through the diet, for example, once weaning of solid foods has been established. However, since vitamin D drops for babies’ side effects can include toxicity from over supplementation, it is always advised to only give your baby vitamin D drops on recommendation from your pediatrician.

Where do we get vitamin D?

The bears are harnessing two of the best natural sources of vitamin D: fish, and the sun!

Known as the sun nutrient, vitamin D is obtained from sunlight exposure to the skin. However, parents are advised to limit their baby’s exposure to UV rays from the sun by dressing baby in appropriate sun covering clothing, wearing a hat, and applying baby sunscreen in the summer months. As babies’ skin needs to be protected from too much sunshine, including vitamin D from dietary sources is also important.

Dietary sources of vitamin D:

  • Eggs (vitamin D is found in the yolks)
  • Fish
  • Dairy (full fat yoghurt, cheese and milk are safe to introduce into baby’s diet from 6 months)


  1. Abrams. Pediatrics. 2013 May;131(5):e1676-83.
  2. Hope Alberta Weiler [Internet]. Montreal, Canada. School of Human Nutrition, McGill University. Vitamin D Supplementation for Infants. 2017 July [cited 2021 April 28]. Available from,and%20through%20supplements%20(1)
  3. Safer Care Victoria. Melbourne, Australia. Victorian Agency for Health Information. Vitamin D deficiency in neonates. 2021 February 17 [cited 2021 April 28]. Available from

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