Poly-Vi-Sol is a liquid multivitamin supplement made by Enfamil, designed specifically for infants and young children. It delivers eight essential vitamins in a single 1 mL daily dose and is one of the most commonly recommended pediatric supplements in the United States, particularly for breastfed babies who may not get enough vitamin D from breast milk alone.
What’s in Poly-Vi-Sol
Each 1 mL serving of the standard formula contains vitamin A (750 IU), vitamin D (400 IU), vitamin E (5 IU), vitamin C (35 mg), and four B vitamins: thiamin, riboflavin, niacin, and B12. The vitamin D content is notable because 400 IU is exactly the daily amount the American Academy of Pediatrics recommends for all infants up to age one.
There’s also a version called Poly-Vi-Sol with Iron, which adds 10 mg of elemental iron per dose. This formulation is typically recommended for breastfed infants starting around four months of age, since breast milk alone doesn’t supply enough iron to meet a growing baby’s needs. The AAP recommends that partially or fully breastfed infants receive 1 mg of iron per kilogram of body weight per day until they’re eating iron-rich solid foods regularly.
Why Pediatricians Recommend It
The main reason Poly-Vi-Sol exists is that breastfed babies have specific nutritional gaps. Breast milk is nutritionally complete in most ways, but it’s consistently low in vitamin D. Babies who drink less than about 27 ounces of commercial formula per day also need a vitamin D supplement, since they’re not getting enough from formula alone. Poly-Vi-Sol covers that gap plus several other vitamins in one dose.
For babies born prematurely, at a low birth weight, or to mothers with gestational diabetes, iron supplementation may need to start even earlier, sometimes within the first month of life. The version with iron addresses this need directly.
How to Give It
The standard dose is 1 mL per day, given by mouth using the dropper or oral syringe that comes with the bottle. You can place it directly into your baby’s mouth or mix it into a small amount of breast milk, formula, or food. Mixing it into a full bottle isn’t ideal because your baby may not finish the entire bottle and would miss part of the dose. Most parents find it easiest to give the drops right before a feeding, when the baby is alert and ready to swallow.
Poly-Vi-Sol is recommended for infants around four to six months of age who are beginning to transition to solid foods, though many pediatricians suggest starting vitamin D supplementation from birth for exclusively breastfed babies (sometimes with a standalone vitamin D drop before switching to the full multivitamin).
Standard Version vs. With Iron
The choice between the two versions usually comes down to whether your baby needs extra iron. Formula-fed babies typically get enough iron from their formula and do fine with the standard Poly-Vi-Sol. Breastfed babies, on the other hand, often need the iron-fortified version starting at four months.
- Standard Poly-Vi-Sol: Eight vitamins, no iron. Best for formula-fed babies or breastfed babies already getting iron from solid foods.
- Poly-Vi-Sol with Iron: The same eight vitamins plus 10 mg of elemental iron. Designed for breastfed or partially breastfed infants who aren’t yet eating iron-rich foods.
Side Effects of the Iron Version
The standard Poly-Vi-Sol without iron rarely causes problems. The version with iron, however, can cause digestive side effects that are common with any oral iron supplement. These include upset stomach, constipation, diarrhea, and belly pain. Many parents also notice that their baby’s stool turns dark green or black, which is harmless and simply reflects how the body processes iron.
If your baby is vomiting frequently, has severe stomach cramps, or passes black tarry stools that look different from the typical iron-related color change, those are signs worth bringing up with your pediatrician promptly.
Iron Drops and Tooth Staining
One side effect that catches parents off guard is tooth staining. Iron-containing liquid supplements can leave brownish or grayish deposits on emerging baby teeth. The staining is extrinsic, meaning it sits on the surface of the tooth rather than damaging the enamel underneath. A dentist can scrape it off, and it tends to stop once the iron source is reduced or the child switches to a non-liquid form of supplementation.
To minimize staining, try placing the drops toward the back of the mouth rather than letting the liquid pool around the front teeth. Gently wiping your baby’s teeth and gums with a damp cloth after giving the dose also helps. Some parents mix the drops into a small amount of food once their baby is eating solids, which limits direct contact with the teeth.