Vitamin D in Children: Deficiency, Food Sources, and Supplements

Key takeaways

• Vitamin D helps growing bones use calcium. [1]
• Breastfed infants need an age-appropriate vitamin D prevention plan. [1]
• Testing is risk-based; high-dose supplements are not routine prevention. [2]

Why vitamin D matters

Vitamin D helps children absorb calcium and build strong bones. It also supports muscles and normal immune function. A deficiency can soften growing bones, causing rickets; in older children and teens, severe deficiency can cause bone pain and muscle weakness. A supplement is not an immune booster or a substitute for a balanced diet. [1]

Parents often hear that almost every child needs a vitamin D blood test. That is not the recommendation for otherwise healthy children. Feeding history, diet, growth, medicines, and medical conditions help the pediatrician decide whether testing would be useful. [2]

How common is vitamin D deficiency in children?

There is no single percentage that applies to every age or definition. A nationally representative U.S. NHANES analysis from 2011–2014 estimated that 0.5% of children ages 1–5 were at risk of deficiency, defined as blood 25-hydroxyvitamin D below 30 nmol/L, equivalent to 12 ng/mL. That historical estimate is not today's rate, a rate for all children and teens, or a measure of rickets. [3]

Studies using a higher cutoff count more children as having low vitamin D. Low dietary intake, a low blood level, and bone disease are different findings. A study's age range, year, and cutoff matter more than a dramatic headline. [2]

Which children may need extra attention?

Breast milk alone usually does not supply enough vitamin D, so breastfed and partly breastfed infants need a prevention plan. Children who avoid fortified foods, have darker skin, or have conditions that reduce fat absorption may also have higher risk. Some medicines and chronic illnesses change vitamin D needs. None of these factors proves a deficiency on its own. [1]

• Tell us if your baby was premature or has a specialist feeding plan.
• Bring the names and labels of any drops, multivitamins, or fortified drinks.
• Ask about persistent bone pain, muscle weakness, delayed motor progress, or concerns about growth.

Food sources and everyday needs

The U.S. recommended daily intake is 400 IU, or 10 micrograms, in infancy and 600 IU, or 15 micrograms, at ages 1–18. These are nutritional intake goals, not instructions for treating a deficiency. For older children, food and supplements both count toward the daily total. [1]

Useful foods include cooked salmon, egg yolks, and vitamin D-fortified milk or suitable fortified alternatives. Check labels: not every yogurt or plant beverage contains vitamin D. Use breast milk or infant formula as your baby's main milk during the first year rather than replacing it with a plant beverage. [1]

Offer foods in age-appropriate textures. For a toddler, a familiar meal with a fortified drink may be more practical than trying to introduce several new foods at once. Do not use unprotected sun exposure as a vitamin D treatment. [1]

When are drops, supplements, or tests appropriate?

Discuss infant vitamin D drops early, including how formula intake contributes. For an older child, review diet and health history before adding a supplement. If a blood test is needed, your clinician will interpret the result in context and choose any treatment and follow-up. Routine screening of healthy children is not recommended simply because winter has arrived. [1] [2]

More is not better. Too much supplemental vitamin D can raise blood calcium and harm the kidneys. Concentrated drops differ in strength, so use only the product and amount agreed with your child's clinician. Avoid stacking a multivitamin, separate drops, and high-dose products without checking the combined amount. [1]

Frequently Asked Questions

Sources

1. NIH Office of Dietary Supplements: Vitamin D, consumer fact sheet
2. NIH Office of Dietary Supplements: Vitamin D, professional fact sheet and screening guidance
3. Herrick et al., 2019: Vitamin D status in the United States, NHANES 2011–2014