Vitamins and Supplements for Children: What They Really Need and When to Give Them

Vitamin D: Why It Is Mandatory

Vitamin D is the most important supplement in childhood. It is essential for calcium and phosphorus absorption, bone formation, immune system development, and even prevention of autoimmune diseases. The problem? Breast milk — although perfect in almost every way — contains little vitamin D, and direct sun exposure for babies is contraindicated by dermatology societies worldwide.

Recommended Vitamin D Doses by Age

Source: Brazilian Pediatric Society (SBP) — Department of Nutrology, 2024. American Academy of Pediatrics (AAP), 2024.

Vitamin D should be given as drops, preferably in the morning, directly in the baby's mouth (do not mix with milk, as it may adhere to the bottle). Formula-fed babies also need supplementation, since the amount in formula is generally insufficient to reach the recommended dose — especially in the early months when intake volume is low. This is a key difference from older US guidelines that exempted formula-fed babies.

Prophylactic Iron: Preventing Anemia

Iron deficiency anemia is the most common nutritional problem in childhood — in Brazil, it affects about 20-30% of children under 5. Iron is essential for hemoglobin production, oxygen transport, brain development, and immune function.

Iron Supplementation Schedule (SBP)

* Individualize with the pediatrician based on formula volume. Source: SBP — Iron Deficiency Anemia Consensus, 2024.

From 6 months, with food introduction, iron-rich foods (red meat, liver, beans, lentils) help complement supplementation — but do not replace prophylactic iron before 24 months. Iron absorption improves when combined with vitamin C (orange, acerola cherry, lemon).

Vitamin A: Brazil's National Supplementation Program

Brazil has a National Vitamin A Supplementation Program that distributes biannual mega-doses to children aged 6 to 59 months in at-risk areas. Vitamin A is essential for vision, immunity, and cell growth.

For children in São Paulo and other major cities, vitamin A supplementation is not always necessary if the diet is varied and rich in sources like carrots, pumpkin, mango, papaya, spinach, liver, and egg yolk. Discuss the need with your pediatrician — in children with food allergies that restrict the diet, assessment is especially important.

Omega-3 (DHA): Evidence and Recommendations

DHA (docosahexaenoic acid) is an essential omega-3 fatty acid, fundamental for brain development, retinal formation, and cognitive function. In the first 2 years of life, the brain triples in size — and DHA makes up about 25% of brain lipids.

The WHO recommends consuming fatty fish twice a week. If that is not possible, DHA supplementation (100-200 mg/day for children) may be considered. For vegans, algae-derived DHA supplements are an effective and safe option.

Zinc: When to Supplement

Zinc is essential for growth, immunity, and wound healing. Zinc deficiency is common in children with diets low in animal protein, chronic diarrhea, or severe picky eating.

Routine zinc supplementation is not recommended for healthy children with a varied diet. The main therapeutic indications are:

• Acute diarrhea: the WHO recommends zinc for 10-14 days as an adjunct treatment, reducing duration and severity
• Growth faltering:when associated with low animal protein intake — assess with growth chart monitoring
• Vegetarians/vegans: phytates in legumes and cereals reduce zinc absorption

Good dietary sources of zinc include red meat, chicken, beans, chickpeas, cashews, and pumpkin seeds. During food introduction, prioritize offering meat from 6 months — it is the best simultaneous source of both iron and zinc for babies.

Probiotics: When They Make Sense

Probiotics are live microorganisms that, in adequate amounts, benefit gut health. The market for pediatric probiotics has grown enormously — but not all products have solid scientific evidence behind them.

The most sensible approach, aligned with integrative pediatrics, is to use probiotics when there is a specific indication, with the correct strain and dose — not indiscriminately. Each strain has a different function; there is no "universal" probiotic.

Multivitamins: Are They Necessary?

The short answer: in most cases, no. Neither the SBP nor the AAP recommend routine multivitamins for healthy children with a varied diet. Supplementation should be specific and targeted (vitamin D, iron) rather than generic.

Exceptions where multivitamins may be considered: children with severe picky eating (fewer than 5 accepted foods), chronic diseases affecting absorption, very restrictive diets due to multiple food allergies, and malnutrition recovery. Even in these cases, prescriptions should be individualized by the pediatrician.

Supplementation for Vegan and Vegetarian Children

Well-planned vegetarian and vegan diets can be adequate for children — but they require rigorous nutritional monitoring and mandatory supplementation of certain nutrients found primarily (or exclusively) in animal-source foods.

Source: SBP — Vegetarian Nutrition in Childhood Manual, 2024. AAP, 2023.

Summary Table: What to Give, When, and to Whom

When to See the Pediatrician

Supplementation should always be guided by the pediatrician. But certain situations merit special attention:

Regular pediatric follow-up is the best way to ensure supplementation is appropriate. During routine visits, I assess growth, diet, and laboratory results to adjust recommendations individually. For expat families, Dr. Paula provides reports in English for your records and international insurance reimbursement.

Summary: What Every Parent Needs to Know

Pediatric supplementation does not need to be complicated. With pediatric care from birth, we ensure each child receives exactly what they need — no more, no less. If you have questions about what your child needs, schedule a consultation for an individualized assessment.