How Much Vitamin D Should I Give My Baby/Infant?

It is absolutely vital that babies get sufficient vitamin D in order to grow and develop properly. They need it to build healthy, strong teeth and bones. If a baby does not receive sufficient levels of vitamin D, a ‘deficiency’ is developed. This can lead to a variety of health problems, including rickets. It is important, therefore, that you make sure that babies get vitamin D, preferably through a D3 supplement, as soon as they are born.

What Is Vitamin D?

Vitamin D is actually a prohormone, as the skin can create it naturally. It is necessary to help our body absorb phosphorus and calcium. If children (and adults for that matter) have insufficient vitamin D levels, they could develop weak bones. The most severe form of this is rickets, a deformity that was almost eradicated but is now making a comeback. Vitamin D, the sunshine vitamin, is produced in our body when the skin is exposed to the UVB rays of the sun. However, for a wealth of reasons, we no longer have sufficient sun exposure to build up levels properly.

How Do We Obtain Vitamin D?

There are a number of different sources from which we obtain vitamin D. The table below highlights this in greater detail.

Source Details
The sun When the skin is exposed to UVB rays, it naturally forms vitamin D. However, in many northern parts of the world, the angle of the sun is not right for vitamin D production during fall and winter months. Babies born in those time periods, therefore, must be supplemented.


However, even in warmer climates, we almost always shield our children from the sun. They wear clothes and hats, sit in the shade and are covered in sun screen. This further prevents them from building up adequate levels of vitamin D.

Food Various foods naturally contain some vitamin D. This includes oily fish, mushrooms and products such as liver. However, these are not products that babies and infants generally consume.


When the link between vitamin D and bone problems was uncovered, a huge global health push ensured that milk, cereals and juices are fortified with the vitamin. It is now federally regulated that infant formula milk be fortified to adequate levels. This means, however, the breastfed babies are at particular risk of having a deficiency.

Supplements Finally, we get levels of vitamin D from supplements. There are two types of supplements, which are vitamin D3 and vitamin D2. D2 is a synthetic form, whereas D3 is natural. It is advisable to supplement with D3, which is more effective. Babies and infants should receive vitamin supplements that have been designed specifically for their age group.

Is My Baby at Risk of Deficiency?

There are a number of common factors that can make a baby at increased risk of deficiency. These include:

• Breastfed babies
• Vitamin D deficient mothers
• Babies with darker skin
• Babies in northern parts of the world
• Babies who may not be able to get it naturally because they have very sensitive skin and therefore can’t be exposed to sunlight
• Babies who don’t get enough vitamin D through their food
• Babies who are under one year old, a time period in which they grow incredibly quickly, which means they also need more vitamin

How Much Vitamin D Should I Give My Baby?

The recommendations can, at times, be a bit vague. This is also because there are so many factors that could contribute to deficiency. Hence, official RDAs (recommended daily amounts), expressed in IUs (international units) are released, but very frequently reviewed. The last review was in 2010, and the RDAs therefore currently stand at:

• 400 IU daily for breastfed babies
• 800 IU daily between October and April for babies who live north of the 55 degree latitude

Always make sure that you speak to your children’s health care provider about the levels that they need.

Breastfed Babies and Vitamin D

It is particularly important that breastfed babies are properly supplemented. All baby formula milk are fortified with vitamin D, but this is not the case with breastmilk. It is important to remember that breast is best, however, so the fact that it is low in vitamin D should not be a deterrent.

Even if you, yourself, do not have a deficiency, it is still important to supplement your baby. It is almost impossible for you to have sufficient levels of vitamin D to support both your own body and still produce plenty in your milk as well. This is why breastfeeding mothers should speak to their health care professionals and determine why they may need additional supplementation. While the RDA for pregnant and breastfeeding mothers is 800 IU, you may want to take up to 2,000 IU.

Your diet is also very important. If you are vegan, for instance, your level of vitamin D will even be lower. Additionally, the vegan diet lacks a range of other vitamins, most notably B12 and D. If babies also have a B12 deficiency, they can become anemic and their nervous system can also be affected. If you are vegan, therefore, you should supplement not just your baby with a multivitamin formula, but also yourself.

Vitamin D and Formula Fed Babies

All formula milk is now fortified with vitamin D. This means that, if your baby was born at full term and you and the baby is fit and healthy, no further supplementation is required. However, if you live in the northern latitudes, you may want to consider a daily 400 IU supplement between October and April.

Vitamin D and Pregnant Women

Whether or not you need supplementation if you are pregnant depends on a number of factors, including:

• Whether you consume any fortified dairy products
• Whether you have sufficient sun exposure on your bare skin
• Whether you already take a vitamin supplement

Types of Vitamin D Supplements

It is important that you give your baby a vitamin D3 supplement. As previously mentioned, this vitamin – cholecalciferol – is the natural form of vitamin D. D2, by contrast, is synthetic and not as effective. It is best to give your baby a liquid type of supplement. Do not choose a multivitamin product to obtain vitamin D levels, however, as many other ingredients in those counteract the workings of vitamin D.

The product label should explain how to give your baby the supplement. Usually, this is counted in the number of drops. It is really important that you check this and follow the instructions properly. A vitamin D overdose is possible. At the same time, its vital to note that you would need to give your children at least five times the recommended amount in order for them to experience any negative effects.

Of course, you should also try to give your baby some direct sunlight exposure. Just 20 minutes in the sun between 11am and 3pm in the spring or summer months can enable our body to produce as much as 10,000 IU. However, babies have very sensitive skin, so you do need to be careful with this. Using sunscreen is not an option, however, since even an SPF 8 stops the skin from absorbing as much as 95% of the vitamin.

Resources and References:

Breastfed Babies Lack Necessary Vitamin D Supplements – Vitamin D supplementation for breastfed babies. (Live Science)
Babies Need Vitamin D Supplements – Vitamin D requirements for babies. (WebMD)
Rickets – General information about rickets. (Vitamin D Council)
Statement on Vitamin D Supplementation for Breastfed Babies – Vitamin D supplements for breastfed babies. (UNICEF)
Breastfeeding and the Use of Human Milk – Breastfeeding and infant nutrition. (American Academy of Pediatrics)
Vitamin D Supplementation – Using vitamin D supplements. (