The American Academy of Pediatrics recommends that all breast fed infants younger than 12 months old need a daily dose of vitamin D. That might be surprising to you! It was to me. It was a pretty new recommendation when I started having babies in 2008, and I wasn’t even made aware of it by my pediatrician.

Not all babies and children are deficient in vitamin D, but a lot are. Even if you’re not sure if your baby is deficient, it’s a good idea to go ahead and supplement.

Why the Deficiencies?

Vitamin D is the sun vitamin. Before humans were indoors so much, vitamin D deficiency was probably very rare. It is absorbed through the skin, so if you’re outside a lot getting direct sunlight on big patches of skin, it’s plentiful. Until recently humans didn’t use sunscreen or live as long as we do now. Because of the risks of skin cancer, we don’t usually spend a lot of time in direct sun without sunscreen anymore. Sunscreen and clothing block much of the vitamin D production. And this is probably the right thing to do.

We live so much longer now. If we are exposed to all that sunlight for all those years, our risks for skin cancer are increased. It’s very hard to get enough vitamin D without lots of sun exposure, because vitamin D is not easy to get through food sources. There are very few foods that are good sources of vitamin D, and most of them are fish.

Why Do People Need Vitamin D?

Vitamin D supports bone health. Vitamin D increases your body’s ability to absorb calcium and phosphorus. These are minerals that are critical for building strong bones and keeping your bones hard and resilient as you age.

When babies and toddlers are severely deficient in vitamin D, they can develop a condition called rickets. Rickets is a disease that causes a softening of the bones which means they can actually start to bend as the baby grows. Older kids and adults can also have an increased risk for broken bones when they are deficient in vitamin D.

How to Give an Infant Vitamin D

Vitamin D can be found over-the-counter at your local drugstore or pharmacy. Sometimes it will be found in the baby aisle with all of the other health and hygiene products. You might also find it with the other vitamins. For babies, you would definitely want to get it in liquid form.

It will come in a small dark glass bottle with a dropper lid. Make sure you read the label. Some of the brands make it very concentrated, and others dilute the vitamin D quite a bit. Usually the more concentrated liquids are more expensive, but they last a lot longer since you’ll only need to give your baby a very small amount. The dose size might even be just one drop!

The recommended dosage for babies is 400 IUs. When you read the bottle label, you will be able to see the concentration shown in IUs. The recommended dose for adults is 600-800 IUs. The bottle will usually tell you how many drops you need to reach the recommended IU level. The vitamin D I use has 600 IU per drop. I like this one because I can use just one drop, but I wouldn’t want to buy this one for a baby since that’s more than the recommended amount. Also, some brands recommend that you refrigerate after opening, so make sure to read the label!

To give your baby the vitamin D, you can either put the drops into a bottle of expressed milk and feed it to your baby that way, or you can just put the drop right into the baby’s mouth. It’s best to get it under the tongue to be sure it goes in. If the vitamin D dose is more than just a couple of drops, it can be hard to get the baby to take it straight. In that case, having some milk to mix it with is a great idea. If you have some pumped milk, you can definitely use that. If you’d rather not pump, that’s ok too! A lot of times you can get enough milk through hand expression and avoid the pump struggles.

What If My Baby is Formula Fed?

As long as your baby is getting at least 32 oz of formula per day, there is no need to supplement with vitamin D, because formula is fortified with vitamin D. In the first month of life, a newborn will not likely be eating 32 oz of formula per day, so it’s good to supplement for at least that first month. Once your baby is eating 32 oz or more per day, they will be getting the recommended amount of vitamin D and you can stop supplementing with vitamin D.

If you are giving your baby breast milk AND formula, you’ll want to supplement with vitamin D until your baby is getting 32 oz of formula per day, and continue to supplement if you never need to give your baby that much formula.

Can You Give Too Much?

Vitamin D is fat soluble so you want to make sure not to give your baby too much. Getting a little too much once in a while is not going to be a big deal, but don’t purposely and routinely give your baby more than the recommended 400 IU dose unless directed by your doctor.

How About Supplementing Mom’s Breast Milk?

A lot of people wonder about getting more vitamin D in the breast milk by making sure the lactating parent is getting enough vitamin D. It is technically possible to fortify the breast milk enough that way, but it’s tough to tell exactly how much vitamin D you would need to take to get there.

In studies, it has been found that taking a very large amount of vitamin D can enrich the breast milk with the right amount of vitamin D for the baby. But it’s hard to tell if that would be too much vitamin D for some people, so it can’t be recommended as the universal strategy for everyone. If you would like to consider this alternative to giving your baby direct supplementation, it would be a good idea to talk to your care provider before starting.