You are home with your newborn, life has been beautifully turned upside down, and suddenly a new question appears: vitamin D. When should you start? How much? And what happens if you miss a day?
Vitamin D is the one supplement that the American Academy of Pediatrics (AAP) and the World Health Organization (WHO) recommend for healthy, full-term babies who are breastfed. The reason is simple: breast milk contains too little vitamin D, and most infants worldwide do not get enough sunlight exposure to produce adequate amounts on their own. This guide gives you all the answers based on current international guidelines.
Why Do Babies Need Vitamin D?
Vitamin D is essential for a baby's skeleton and teeth to develop normally. The vitamin also helps the immune system function properly.
The body produces vitamin D when sunlight hits the skin. However, in many regions — particularly during autumn and winter months — sunlight is too weak or too infrequent to produce enough vitamin D. Additionally, health authorities advise against exposing babies under 6 months to direct sunlight, because their skin barrier is not fully developed and the risk of sunburn is high.
Breast milk gives a baby almost everything it needs — but not enough vitamin D. Even if you as a breastfeeding parent take vitamin D supplements yourself, the level in breast milk remains too low to meet your baby's needs.
Health authorities in many countries, including the United States, Canada, the United Kingdom, and most of Europe, recommend vitamin D supplements for all breastfed infants. This is a year-round recommendation, not just for winter months.
When Should You Start Giving Vitamin D?
Start from around 1–2 weeks of age. This is the recommendation from the AAP for all breastfed babies.
You do not need to wait for a pediatrician appointment — you can begin at home as soon as you have settled into a routine. Most parents find it easiest to give the drops as part of a morning routine.
The Right Vitamin D Dose
Fully breastfed babies: 400 IU (10 micrograms) per day — the AAP and WHO standard recommendation
Partially breastfed babies:
- If receiving less than 1 liter (about 32 oz) of formula per day: give 400 IU drops
- If receiving 1 liter (about 32 oz) or more of formula per day: no drops needed
Babies fully on formula: Do not need a separate vitamin D supplement. Standard infant formula is fortified with vitamin D, and 1 liter per day provides the recommended amount.
Unsure whether your baby needs a supplement? Calculate how much formula your baby gets in a day. If it reaches about 1 liter (32 oz), vitamin D is covered. Less than that, give drops.
Vitamin D Drops: What to Buy
Most vitamin D drops for infants use cholecalciferol (D3) in a carrier oil base. Common products available in pharmacies and baby stores include:
D-Drops Baby A widely used product in North America. One drop provides 400 IU. Contains just two ingredients: cholecalciferol and fractionated coconut oil. Free of gluten, dairy, and preservatives.
Zarbee's Naturals Baby Vitamin D A popular option in the United States. Provides 400 IU per dose.
Wellbaby Vitamin D Drops Widely used in the United Kingdom. One drop provides 400 IU.
Different products have different concentrations per drop. Always read the label carefully, and do not switch products without checking the dose. Do not give cod liver oil in addition to vitamin D drops — cod liver oil contains vitamin D and doubling up can cause toxicity.
Cod Liver Oil Is Not Recommended in the First Year
This surprises many people. Cod liver oil was a classic remedy for decades, but current guidelines have changed.
The reason: cod liver oil in recommended amounts provides too little vitamin D for young infants, while providing unnecessarily high amounts of the omega-3 fatty acid DHA — which most babies already get enough of through breast milk. The AAP and WHO therefore recommend pure vitamin D drops rather than cod liver oil during the first year of life.
How to Give the Drops — Practical Tips
Vitamin D drops are oil-based and typically flavorless. Most babies accept them without trouble.
How to give them:
- Hold the bottle upright and drop directly into the baby's mouth
- Alternatively, mix the drops into a small amount of breast milk, formula, or puree (once solids have started)
- Do not mix into food that you heat — heat can degrade the vitamin
Storage: Most products can be stored at room temperature (15–25°C / 59–77°F) for up to 6 months after opening, but cooler storage helps preserve potency throughout the shelf life.
Give the drops at the same time every day — ideally with the first morning feed. This makes it easier to remember and avoids wondering if you have already given them that day.
How Long Should Your Baby Take Vitamin D?
The AAP recommends that breastfed babies continue vitamin D supplementation (400 IU per day) until they are consuming at least 1 liter (32 oz) of vitamin D-fortified formula or whole milk per day, or until they reach 12 months.
After 12 months, if your toddler is eating a varied diet including vitamin D-rich foods and getting some sun exposure, you can discuss with your pediatrician whether to continue supplementation. Many health authorities recommend continuing through early childhood, particularly in regions with limited sunlight in winter.
Vitamin D from Food — What Can Baby Eat?
When your baby starts solid foods around 6 months, some foods can contribute to vitamin D intake — but supplements remain important throughout infancy.
Good natural sources of vitamin D:
- Fatty fish such as salmon, mackerel, and sardines (from 6 months, well-cooked)
- Egg yolks (from 6 months)
- Fortified foods such as formula and some breakfast cereals
Note that it is difficult to meet an infant's vitamin D needs through food alone. Supplements are necessary regardless of diet during the first year.
Signs of Vitamin D Deficiency in Baby
Mild deficiency rarely causes obvious symptoms in infants. Severe vitamin D deficiency can lead to rickets — a condition that affects bone formation and skeletal development.
Signs that may indicate vitamin D deficiency:
- Delayed closing of the fontanelle (soft spot on the skull)
- Soft or unusually shaped skull
- Visible leg bowing when the baby begins to stand
- Delayed teething
- Irritability and increased crying without a clear cause
- Frequent infections
Contact your pediatrician if you are concerned about your baby's development or suspect vitamin D deficiency. The doctor can order a simple blood test to check vitamin D levels. Do not increase the dose on your own.
Safety: How Much Is Too Much?
Vitamin D is fat-soluble and can accumulate in the body. It is important to stick to the recommended dose.
Upper safe limits according to the AAP:
- 0–6 months: maximum 1,000 IU (25 micrograms) per day
- 6–12 months: maximum 1,500 IU (37.5 micrograms) per day
The recommended dose of 400 IU is far below these limits. Problems only arise if cod liver oil is given in addition to drops, or if adult-strength products are used by mistake.
Dosing Table by Feeding Type
| Baby's nutrition | Vitamin D drops per day | Amount of vitamin D |
|---|---|---|
| Fully breastfed | Standard dose (400 IU) | 10 micrograms |
| Partially breastfed (less than 1 L formula/day) | Standard dose (400 IU) | 10 micrograms |
| Partially breastfed (1 L+ formula/day) | No drops needed | Covered by formula |
| Fully formula-fed | No drops needed | Covered by formula |
Frequently Asked Questions
What do I do if I forgot to give the drops today?
Give a normal dose when you remember. Do not give a double dose to make up for what you missed — it is not necessary.
Can I give vitamin D to a newborn right away?
Start from about 1–2 weeks of age. Most maternity wards or pediatricians will advise you about this before you leave the hospital.
I am breastfeeding and healthy — do we still need drops?
Yes. Even the healthiest breast milk contains too little vitamin D to meet your baby's needs. This applies to all breastfeeding parents, regardless of diet or personal vitamin D levels.
Is there a difference between D2 and D3?
Most products for infants contain D3 (cholecalciferol), which is the form the body uses most efficiently. The majority of infant vitamin D drops on the market use D3.
Should I give drops when my baby is sick?
Yes, continue with drops as normal. The only exception is if the baby is vomiting everything they eat — in that case, wait until they have recovered.
Does my baby need vitamin D in summer too?
Yes, for babies under 6 months especially. Health authorities advise against direct sun exposure for young infants because their skin is too sensitive. Even in summer, the recommendation to supplement remains.
We are a vegan family. Does my baby need anything else?
Yes. If you are breastfeeding on a fully plant-based diet, your baby may also need vitamin B12 and iodine in addition to vitamin D. When your baby moves beyond exclusive breastfeeding, speak with your pediatrician about a complete infant multivitamin. This is especially important on a vegan diet.
Can a baby get too much vitamin D?
Yes, vitamin D is fat-soluble and can build up. But the recommended 400 IU dose is far below the upper safe limits. The risk only arises if cod liver oil is given alongside drops, or if products meant for adults are used. Stick to one product at the recommended dose.
From the AAP: Current guidelines do not recommend cod liver oil in the first year of life as a primary vitamin D source. Use pure vitamin D drops during the first year, and discuss transitioning to a broader supplement (if needed) with your pediatrician after 12 months.
Vitamin D is a small habit with a big impact. Four hundred IU per day from about 1–2 weeks of age — that is all it takes. If you have questions about your baby's health and development, bring them up with your pediatrician at the next visit.
Sources
- American Academy of Pediatrics (AAP). "Vitamin D Supplementation for Infants." 2022.
- World Health Organization (WHO). "Vitamin D Supplementation in Infants and Young Children." 2022.
- Centers for Disease Control and Prevention (CDC). "Vitamin D." 2024.
- National Institutes of Health (NIH). "Vitamin D Fact Sheet for Health Professionals." 2024.