Vitamin D For Babies: Why And How Much Do They Need ?

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Vitamin D is vital for a baby’s bones development. The nutrient is easily available but sometimes the baby may have deficiency, especially if they are breastfed.

Why is vitamin D important and how much of it does a baby need? What are the repercussions of vitamin D deficiency in a baby?

MomJunction answers all these questions as we tell you about vitamin D for babies, its sources, supplements and more.

What Is Vitamin D?

Vitamin D is a compound that is naturally produced by the body when exposed to sunlight.

There are two types of vitamin D:

  • vitamin D3 also called cholecalciferol
  • vitamin D2 also known as ergocalciferol (1)

Vitamin D3 is produced within the body. A compound called 7-dehydrocholesterol in the skin absorbs sunlight and forms the previtamin D3. This passes through the bloodstream to the liver and then the kidneys for further processing; it then transforms into the active vitamin D (2).

Plants and fungus synthesize vitamin D2 on exposure to sunlight. Vitamin D2 is usually present in the supplements although vitamin D3 supplements also exist.

Vitamin D2 has to pass through the same biochemical reactions as vitamin D3 to convert into active vitamin D.

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[ Read: Vitamin C Foods For Babies ]

Why does your baby need vitamin D?

Here is how vitamin D helps keep your baby healthy (3):

  1. Strong bones: It is perhaps the best-known use of vitamin D. The body needs sufficient quantities of vitamin D to retain enough phosphorus and calcium in the bones. If the baby’s diet lacks vitamin D, then their bodies could drain out calcium and phosphorus through urine. It could also lead to a deficiency of these elements.
  1. Supports metabolic activities: The body needs adequate levels of calcium and phosphorous to carry out several metabolic activities. Vitamin D makes sure that the body keeps a healthy stock of these nutrients.
  1. Robust immunity: Vitamin D improves the body’s innate immunity and minimizes the chances of developing an autoimmune disease.
  1. Insulin production: The vitamin has a role to play in the secretion of insulin by the pancreas. Research shows that the deficiency of vitamin D could lead to a drop in insulin production.
  1. Essential for blood pressure regulation: While infants may not have the risk of high blood pressure (hypertension), sufficient vitamin D helps the body regulate the blood pressure.

Your baby‘s body will be able to do all these functions if it gets adequate vitamin D.

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How Much Vitamin D Does Your Baby Need?

The following is the recommended dietary allowance (RDA) of vitamin D for babies and toddlers in milligrams per day (μg/day), and its equivalent in international units (IU/day):

AgeVitamin D in μg/dayVitamin D in IU/day
0-6 months10400
6-12 months10400
1-3 years15600

The RDA of vitamin D varies for babies and toddlers but is the same for both boys and girls.

If the baby is continuously missing the RDA of vitamin D, it could lead to some unwanted repercussions.

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[ Read: Healthy Foods For Babies ]

What Are The Effects Of Vitamin D Deficiency?

A baby who does not get sufficient vitamin D runs the risk of developing the following conditions:

  1. Rickets: Rickets is a condition where the bones are unable to retain adequate calcium and phosphorous. While it could happen due to various reasons, often it is due to the lack of vitamin D in the body (4).
  1. Hypocalcemia: The calcium levels in the blood drop severely, leading to the risk of several metabolic problems (5). Hypocalcemia is widely noted among children with a severe deficiency of vitamin D.
  1. Osteopenia: A dip in bone density makes them brittle and susceptible to fracturing (6). This condition arises due to insufficient absorption of calcium by the small intestine due to low vitamin D levels.
  1. Muscle weakness: A baby with vitamin D deficiency is quite likely to be lethargic and have low energy levels due to muscle weakness.
  1. Low immunity: Research shows that children with low levels of vitamin D have a hindered immunity. The deficiency may leave the body susceptible to pathogen attacks. Studies have found that those suffering from tuberculosis tend to have lower levels of vitamin D. It suggests that vitamin D deficiency can leave the body vulnerable to the tuberculosis bacteria (7).
  1. Susceptible to respiratory infections: Some studies suggest that children with vitamin D deficiency have a higher chance of developing cold, flu, and other respiratory illnesses. Vitamin D stimulates the function of immune cell proteins that fight the pathogens.
  1. Cancers: Deficiency in vitamin D has been linked to some types of cancer (8). In the absence of vitamin D, the cells could proliferate rapidly, leading to cancer.
  2. Growth stunting: Vitamin D deficiency can also keep a child from reaching her/his genetically programmed height.
  3. Hormonal imbalance: It also functions as a hormone with many other metabolic functions in the body, including regulation of the immune system and cell growth.

Certain risk factors increase the likelihood of vitamin deficiency in the baby.

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What Are The Risk Factors For Vitamin D Deficiency?

The following factors increase the chances of a baby developing vitamin D deficiency:

  • Low sunlight exposure: The single major risk factor is little exposure to sunlight. Babies who do not get enough sunlight tend to have low levels of vitamin D in the body. You may not take newborns out in intense sunlight, but older infants and toddlers can certainly spend some time out under the sun.
  • Skin color: Individuals with darker skin tone tend to synthesize lesser vitamin D on exposure to the sun than those with lighter skin tone.
  • Exclusive breastfeeding: According to the American Academy of Pediatrics, human milk is low in vitamin D (9). It means infants who are exclusively breastfed run the risk of developing the deficiency.
  • If the mother is deficient in vitamin D: Vitamin D status of the baby depends on that of the mother. If the baby is not producing enough vitamin D from sunlight and even the breast milk is deficient in vitamin D, it might hamper the growth and development of the baby.

The good news is you can prevent vitamin D deficiency.

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How To Prevent Vitamin D Deficiency In Babies?

Take the following measures to avoid the deficiency (10):

  • Administer vitamin D supplements. Ensure that your baby is getting 400IU of vitamin D from birth to the age of 12 months through supplements.
  • Adequate exposure to sunlight: A few minutes of sunlight every day allows the body to produce some vitamin D, which can add to the supplementation. Toddlers can spend time playing outdoors in the morning sun when the risk of sunburns is the lowest.
  • Maternal vitamin D supplementation: If you are a lactating mother, then take the supplements yourself to infuse extra vitamin D in the breast milk. The RDA of vitamin D for lactating women is 15μg/day or 600IU/day. Studies suggest that even after an everyday intake of 400IU vitamin D by the lactating mother, the levels of vitamin D in the breast milk were not more than 78IU per liter of milk. It means you will still have to give vitamin D supplements to your baby.
  • Give vitamin D-rich foods. Once your baby is older than six months, introduce vitamin D-fortified infant cereal and crackers. After 12 months, you can add a wide variety of foods, including vitamin D-fortified cow milk.

Next, we’ll tell you about the vitamin D-rich foods you can give to your baby.

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[ Read: Baby Fiber Rich Foods ]

Food Sources Rich In Vitamin D

The following food items are good sources of vitamin D:

  • Vitamin D fortified food: Infant cereal, crackers for toddlers, formula
  • Fatty fish: Salmon, tuna, and mackerel
  • Egg: Especially the egg yolk
  • Vitamin D fortified milk: Cow or buffalo milk with added vitamin D

Foods like fish, egg, and cow/buffalo milk can be introduced only after the age of 12 months (11). So how can babies less than one year, who are breastfeeding, get vitamin D?

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How Can You Give Vitamin D To Babies Less Than Six Months?

Here are the two best sources of vitamin D for babies below one year who cannot eat vitamin D-rich food and infants below six months who cannot have anything other than breast milk:

  • Vitamin D drops: Medical experts state that a baby should start having vitamin D drops a few days after birth (12). It is mandatory for all the babies to receive vitamin D supplement from birth to 12 months. Vitamin D drops are administered using a dropper and contain the RDA 400IU of vitamin D. These supplements are usually in the form of vitamin D2 or D3 synthesized under sterile laboratory conditions.
  • Vitamin D fortified formula: All formula powders are fortified with at least 400IU of vitamin D. If your baby has 32oz (946.3ml) a day, then he/she will get sufficient vitamin D from formula alone and will not need supplementation.
  • Since vitamin drops are a major source of vitamin D for your baby, you need to know the right way to administer them.

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How To Give Vitamin D Drops To The Baby?

Giving the drops to your baby is easy and here is how you do it:

  1. Most vitamin D supplements contain the RDA of 400IU in about 1ml of supplement. It means you need to give 1ml to meet the RDA of vitamin D.
  1. Take a dropper and draw the supplement into it.
  1. Place the baby on your lap.
  1. Gently insert the dropper into the baby’s mouth and aim it at a spot where the baby would have their lower second molar (the last teeth at the back of the lower jaw). You can aim the dropper’s end either at the lower right molar or the left one depending on your convenience.
  1. Aiming at the lower second molars ensures that all the liquid goes straight down the throat. If you point the dropper straight, barely into the mouth and towards the tongue, then it is easier for the baby to spit it out with saliva. Putting the dropper straight into the mouth can cause gagging.
  1. Once the dropper is in the correct position, press the rubber end of the dropper to release the liquid. Gently remove the dropper, and keep the baby in the same position for a minute to let the liquid trickle into the throat.

If the baby spits out some supplement, then do not re-dose.

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[ Read: Is Spinach Good For Babies? ]

How Long Do Babies Need Vitamin D Drops?

Vitamin D drops are mandatory until the age of 12 months unless the infants are having 32oz (946.3ml) of formula per day.

Exclusively breastfed babies surely need supplementation. Once your baby is older than 12 months, they can have vitamin D fortified cow milk, or you may even consider giving vitamin D-fortified formula in case your baby did not have it yet.

If the baby is getting their RDA from vitamin D-fortified food, then you can skip the drops.

You are quite likely to have some other questions about vitamin D for babies, and we address them in the section below.

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Frequently Asked Questions About Vitamin D For Babies

1. What if I accidentally gave more vitamin D to my baby?

Adverse effects are highly unlikely on ingesting some extra drops of vitamin D supplement. However, toxicity does exist and can cause problems like an excess accumulation of calcium in the body (13).

It is still improbable for your baby to have more than 1000IU of vitamin D per day for several days to develop toxicity (14). An accidental drop or two from the vitamin D supplement is also not likely to do any harm unless you do it every day for several days.

Vitamin D from food and sunlight will not cause such toxicity.

Therefore, you can prevent vitamin D toxicity by checking the quantity of vitamin D in the supplement and giving the exact number of drops as prescribed by the doctor.

2. Can I give vitamin D to my baby as part of a multivitamin supplement?

Yes. There are several multivitamin supplements for infants that also include vitamin D. When choosing multivitamin drops, measure the quantity of liquid accordingly. Read the label carefully before measuring out a portion and consult your doctor if you have any doubts.

3. Can I give my baby organic vitamin D drops?

Yes. You can give your baby vitamin D supplements certified as organic. Make sure that there are no other additives or substances in the supplement. You may consult the doctor before giving the supplement.

4. Is there any test to check the baby’s vitamin D levels?

Yes. If your doctor suspects that the baby has low levels of vitamin D, then they can check it through a blood test (15).

Vitamin D is essential for healthy bones, muscles, and the circulatory system. It is also crucial for keeping the baby’s immune system in top-notch condition. While vitamin D is always available through sunlight, we cannot expose infants to sunlight for long due to the risk of sunburns.

[ Read: First Food Recipes For Babies ]

Vitamin D drops and fortified food can help you meet the RDA. Once your baby gets older, he/she can eat a wide variety of foods to ensure that the body always has adequate vitamin D reserves.

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Do you have any other questions to ask us on vitamin D? Let us know in the comments section below.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. On call: Vitamin D2 or D3?; Harvard Health Publishing (2010)
2. M. F. Holick; Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease; The American Journal of Clinical Nutrition (2004)
3. J. Higdon; Vitamin D; Oregon State University(2000)
4. G. M. Tannin; Vitamin D Deficiency and Rickets: A Guide for Families; American Academy of Pediatrics
5. M. S. Cooper, N. J L. Gittoes; Diagnosis and management of hypocalcaemia; Journal:BMJ. 2008
6. Osteopenia; Hospital for Special Surgery
7. Vitamin D and Health; Harvard T. H. Chan
8. Skin cancer patients more likely to be deficient in vitamin D, study finds; Stanford Medicine (2010)
9. Vitamin D Deficiency and Rickets; American Academy of Pediatrics(2015)
10. C.L.Wagner, F.R.Greer; Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents;American Academy of Pediatrics (2008)
11. Feeding Your Toddler – Ages 1 to 3 Years; Cleveland Clinic
12. Vitamin D; Centre For Disease Control And Prevention(2018)
13. Vitamin D Supplementation in Infants, Children, and Adolescents,; American Academy of Family Physicians
14. Vitamin D Toxicity in Children: A Rare But Preventable Problem; Weill Cornell Medicine (2014)
15. Memo to Pediatricians: Screen All Kids for Vitamin D Deficiency, Test Those at High Risk; Johns Hopkins Medicine; (2012)


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