Updated guidance highlights the importance of age-specific vitamin D intake for children, warning against indiscriminate supplementation and emphasising natural sources like food and sunlight, while recognising the risks of overconsumption.
Giving children vitamin D is often treated as a simple way to support growth, but the need for supplements depends on age and feeding pattern. Vitamin D helps the body absorb calcium and build strong bones, and a shortfall can lead to rickets, a condition that leaves bones soft and weak, according to the US Centers for Disease Control and Prevention and MedlinePlus.
The CDC recommends 400 international units, or 10 microgrammes, a day for babies from shortly after birth until 12 months old, and 600 IU, or 15 microgrammes, a day for children aged 12 to 24 months. Breastfed and partially breastfed infants should get a daily 400 IU supplement because breast milk usually does not supply enough vitamin D on its own, the agency says.
Infants who rely entirely on vitamin D-fortified formula are treated differently. The CDC says babies who drink at least 32 ounces, or about 950 millilitres, of formula a day generally do not need extra vitamin D. The same guidance also notes that sunlight is not a dependable substitute for infants, as exposure can be limited by clothing, sunscreen, skin tone, weather and geography.
Parents should also be cautious about assuming that more is better. The National Institutes of Health warns that excessive vitamin D can raise calcium levels in the blood and cause health problems. A systematic review published in 2026 found that 400 IU a day is enough to keep vitamin D levels adequate in most healthy full-term babies, though needs can vary in some children and should be reviewed with a clinician.
Food can help, too. The CDC and MedlinePlus list fatty fish, egg yolks, beef liver, cheese and fortified products such as milk, yoghurt, cereals and some juices as sources of vitamin D. For that reason, doctors advise families not to adjust doses on their own and to check with a health professional if they are unsure whether a child needs a supplement.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
