A Guide To Vitamin D For Babies

The rundown on vitamin D for babies

• Vitamin D supports your baby’s bones, muscles and immune function.
• It is difficult to get enough vitamin D from breast milk or foods alone. Most vitamin D is made in the skin during sun exposure.
• Gentle, indirect outdoor time can help with vitamin D production, but sun safety is essential.
• Baby supplements containing vitamin D can be a great way to reach recommended daily intake.

Vitamin D plays an important role in healthy growth and development for babies, especially when it comes to their bones, muscles and immune function.^1,2 It’s one of those nutrients that does a lot of work behind the scenes, but it’s also something parents can have questions about. Is my baby getting enough? Do they need additional support? How can I spend time outdoors with my baby?

This guide walks through what you need to know about vitamin D for a baby, including how they get it, the signs of low levels, when supplements might help and how to approach sun exposure safely.

The role of vitamin D in babies

Vitamin D plays an important role in your baby’s growth during their first year. Here’s how it supports their growing bodies:

• Helps the body absorb calcium and phosphate, the minerals needed to build strong bones and teeth²
• Supports healthy muscle function²
• Contributes to overall skeletal development, which is especially important during these rapid early months of growth³
• Helps the immune system regulate how the body responds to everyday germs.⁴

Because vitamin D isn’t found in many foods and babies have limited sun exposure, some infants may struggle to get enough through feeds and lifestyle alone.

Vitamin D deficiency symptoms in a baby

Low vitamin D levels can show up in different ways, and the signs are often subtle. Indications or conditions that may involve low vitamin D include:

• Slower growth or delayed motor development²
• Frequent infections like colds⁴
• Food allergy, especially egg and peanut⁶
• Soft or weakened bones, which can happen when deficiency continues over time²

These signs will often overlap with other childhood conditions, so it’s always best to speak with your baby’s doctor if you’re concerned.

Do babies need a vitamin D supplement?

Whether a baby needs a vitamin D supplement can depend on a range of factors such as their feeding and lifestyle.

Breastmilk is the optimal source of nutrition for infants; however, it provides limited vitamin D. Infant formula contains vitamin D, but it may not be enough.⁵ Australian maternity services recommend vitamin D supplementation for all infants under 6 months, regardless of feeding method, to help meet requirements. Some babies may also be more exposed to lower vitamin D if their mothers had low vitamin D during pregnancy, they have limited sun exposure, have darker skin, or live in households where other family members have dietary deficiency.⁷

What to expect with a baby vitamin D supplement

Vitamin D supplements for babies come in different formats, including tablets, liquids or powders that can be mixed into breast milk, formula or food. Vitamin D may also be present in supplements with other nutrients. They may be taken daily, or as directed on the product label.²

It is important to follow advice from your doctor on the dosage, to ensure that there are no medicine or supplement interactions.

While issues are not expected when following guidance from your healthcare professional, it’s important to speak to your doctor about any concerns you have on side effects or dosage.

What is the best age to expose a baby to the sun for vitamin D?

The body can naturally make vitamin D when exposed to UVB light. Babies can start spending short periods of time outdoors from birth, but indirect, gentle sunlight is recommended rather than direct sun exposure. This is because a baby’s skin is more sensitive than an adult’s and can burn quickly

Short outdoor time in the shade, or brief play in the morning or late afternoon when UV levels are lower, is typically enough for most babies while still prioritising sun safety.² Babies under 12 months should be kept out of direct midday sun, dressed in protective clothing, and have their pram or play area shaded. Widespread use of sunscreen is not recommended for babies under 6 months due to the sensitivity of their skin, with reactions more likely to occur. Prioritise other forms of sun protection like shade and hats as much as possible.

Supporting your baby’s vitamin D needs

Vitamin D plays an important role in your baby’s growth, bone development and immune support. Many babies do not get as much vitamin D as they need through feeding and sun exposure, therefore may benefit from a supplement.

If you’re unsure whether your little one needs vitamin D supplement, your maternal child health nurse or GP can guide you based on your baby’s age, environment and overall health.

Looking for more support on your parenting journey? Explore the Biostime Parent Lounge for articles such as the run down on baby eczema and creating a restful night time routine

References

1. Maron WA. Vitamin D in infancy and early childhood: bone growth, immune development and deficiency risks. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10060648
2. Royal Children’s Hospital Melbourne. Vitamin D. Available at: https://www.rch.org.au/kidsinfo/fact_sheets/Vitamin_D
3. Healthy Bones Australia. Your Bone Health – Vitamin D & Bone Health. Available at: https://healthybonesaustralia.org.au/your-bone-health
4. Dietitians Australia. Vitamin D. Available at: https://dietitiansaustralia.org.au/health-advice/vitamin-d
5. The Women’s Hospital. Vitamin D for you and your baby. Available at: https://www.thewomens.org.au/images/uploads/fact-sheets/Vitamin-D-for-you-and-your-baby_220429.pdf
6.  Murdoch Children’s Research Institute. Investigating allergies: food allergy capital. Available at: https://www.mcri.edu.au/news/news-stories/investigating-allergies-food-allergy-capital
7. Better Health Channel (Victoria State Government). Vitamin D. Available at: https://www.betterhealth.vic.gov.au/health/healthyliving/vitamin-d
8. Cancer Council Australia. Sun protection for babies and children. Available at: https://www.cancer.org.au/about-us/policy-and-advocacy/prevention/uv-radiation/related-resources/sun-protection-babies