Vitamins for kids, what evidence supports

The practical recommendation

If you are buying for a generally healthy child, do not start with a full children’s multivitamin. Start with the child’s actual risk: vitamin D is the most common routine supplement need, iron is a targeted need, and vitamin B12 is a diet-pattern need. A picky eater who still consumes milk, yogurt, eggs, meat, fortified cereal, beans, fruit, and some vegetables usually does not need 12 vitamins in candy form. A breastfed infant, a child with low vitamin D intake, a vegan child, or an adolescent with heavy periods is a different case.¹²3

That distinction matters because children’s supplements are often marketed as nutritional insurance. Insurance is useful only when it covers a real risk. For kids, the real risks are not evenly spread across the alphabet of vitamins. They cluster around a few nutrients, age windows, and eating patterns.

What the evidence says about the contenders

Vitamin D has the clearest case. It supports calcium absorption and bone mineralization, and few foods naturally contain much of it. In the United States, fortified milk and some fortified foods carry much of the dietary load, but intake still varies by age, diet, sun exposure, skin coverage, and milk intake.¹ The American Academy of Pediatrics advises 400 IU (10 mcg) per day for infants up to age 1 and 600 IU (15 mcg) per day for children older than 1 year, with supplements used when diet does not provide enough.²

For infants, the rule is more concrete. Exclusively or partially breastfed babies generally need 400 IU of vitamin D daily beginning soon after birth. Formula-fed infants may not need separate drops if they drink enough vitamin D fortified formula, commonly described as about 32 ounces or 1 liter per day.²⁵ This is not a wellness trend. It is a narrow, age-specific recommendation tied to low vitamin D content in human milk and the need to protect normal bone development.

Iron is the most important “not actually a vitamin” to keep in the conversation. Healthy full-term infants are born with iron stores, but those stores decline during infancy. The AAP clinical report recommends iron attention in early life, including supplemental iron for exclusively breastfed full-term infants starting at 4 months if iron-rich complementary foods are not yet providing enough, and higher-risk protocols for preterm or low-birth-weight infants.3 Older children may need evaluation if they have very limited diets, high cow’s milk intake, symptoms of anemia, endurance training with poor intake, or heavy menstrual bleeding. But iron should not be casually added “just in case.”

Vitamin B12 is mainly a diet question. Children who eat animal foods usually get B12 from meat, fish, dairy, and eggs. Children eating vegan diets need reliable B12 from fortified foods or a supplement, because unfortified plant foods are not dependable sources. This is one of the few cases where a supplement can be simpler and safer than hoping a child consistently eats enough fortified foods.

A broad multivitamin is the weakest default choice. It can be reasonable as a short-term backstop for a child with a highly restricted diet, feeding disorder, poor growth, food insecurity, or a clinician-identified gap. But for the average child, a multivitamin often duplicates nutrients already supplied by fortified foods. Gummies can also train the wrong habit: a daily sweet that looks and tastes like candy but contains active ingredients. That is especially concerning when the product contains iron.⁴

The audience-specific factor that drives the choice

Age is the first filter. Babies are not small school-age kids. Breastfed infants need vitamin D because their diet is intentionally narrow and human milk alone usually does not supply enough. Toddlers need attention to iron if milk displaces iron-rich foods. School-age kids usually need food structure more than pills. Adolescents may need targeted attention to vitamin D, iron, or B12 depending on diet, menstruation, sports, body size changes, and sun exposure.

Diet pattern is the second filter. A vegetarian child who eats dairy and eggs may be fine on B12 but still need iron planning. A vegan child needs B12 reliability. A child who avoids milk and fortified alternatives may need vitamin D help. A child with celiac disease, inflammatory bowel disease, bariatric surgery, chronic medication use, or other medical issues belongs in a clinician-guided category, not the generic vitamin aisle.

The third filter is dose. For vitamin D, look for a child-appropriate product that provides the recommended daily amount without stacking multiple supplements. For iron, use the dose your pediatrician recommends and store it securely. For B12 in vegan children, consistency matters more than a “complete” multivitamin label.

When this recommendation might not fit

A multivitamin can make sense when the alternative is a persistent, documented pattern of inadequate intake. Some children with autism-related food selectivity, avoidant restrictive food intake disorder, chronic illness, poor growth, or recovery from undernutrition may need broader supplementation. In those cases, the right product depends on what the child actually lacks, what they will take, and what their clinician is monitoring.

There is also a practical case for a simple multivitamin without iron when a parent and pediatrician agree that the child’s diet is temporarily narrow. The goal should be to bridge a gap, not to make the supplement the nutritional plan.

What to buy, without pretending brands are evidence

At the form level, choose based on age and safety. Infants need liquid drops. Children under 3 should not use hard chewables unless their clinician specifically says they can safely chew them. For older kids, a chewable or liquid is fine if the dose is appropriate. Avoid megadose products, adult supplements, and “immune” blends that add herbs or high-dose fat-soluble vitamins.

For vitamin D, vitamin D3 is common and effective, but the bigger issue is dose and adherence. For iron, do not buy an iron-containing children’s multivitamin unless there is a clear reason. Federal labeling requires strong warnings on iron-containing products because accidental overdose can be fatal in children under 6.⁴ Store all supplements like medication, not snacks.

The best answer is not “kids need vitamins.” It is narrower: kids need the nutrients their diet, age, sun exposure, and health status fail to provide. For many families, that means vitamin D. For some, it means iron or B12. For most, it does not mean a daily gummy multivitamin as the default.