Essential Vitamin D Guide for Parents: Preventing Deficiency in Children Under 5 (Updated for 2026)

Vitamin D is crucial for your child’s healthy growth and development, especially in early years. It supports bone and tooth strength, muscle function, and immunity, and deficiency is common in the UK due to limited sunlight exposure and diet.

This guide explains what vitamin D is, why it matters, how much children need, and practical ways to ensure they get enough throughout the year.

So let's dive right into our Essential Vitamin D Guide for Parents!

What Is Vitamin D and Why It Matters

Vitamin D is a fat-soluble vitamin that helps the body absorb calcium and phosphorus — key nutrients for building strong bones and teeth. It also plays a role in immune health and muscle function.

Your body can make vitamin D when skin is exposed to sunlight, but in the UK this is often insufficient from autumn through early spring.

How much Vitamin D Does your Child Need?

Children from the age of 1 year and adults need 10 micrograms (mcg) of vitamin D a day. This includes pregnant and breastfeeding women, and people at risk of vitamin D deficiency.

Babies up to the age of 1 year need 8.5 to 10 micrograms of vitamin D a day.

Formula-fed babies taking enough formula usually don’t need extra supplements because formula is fortified.

If taking supplements, always follow label instructions and consult your GP or health visitor if you’re unsure.

Common Causes of Vitamin D Deficiency in Children and the Risks

Prolonged deficiency in children can result in rickets - the main signs of which are skeletal abnormalities (for example bowed legs) with bone pain or tenderness and muscle weakness.

Cases of rickets amongst British children aged under five have increased in recent years, rising since 1997 – but this disease was originally eliminated in Britain during Victorian times – so why is it returning at such a high rate?

It’s important to remember we’re not seeing more cases of rickets because of neglect or poor parenting.

Several factors have all combined, contributing to children having a lower intake of vitamin D.

Let’s have a look at some of these factors:

• Sunscreen use (important for skin safety) can reduce vitamin D production.

• Children opting to stay inside more, using technology for play and learning.

• Cultural differences such as ones which mean children don’t spend as much time outdoors or are more covered up.

• Lack of exposure to the sun in pregnant women can result in exposing the foetus to the deficiency.

• Lower sun synthesis for children with darker skin tones.

These are just a few of the factors that can affect your little one’s intake of Vitamin D – with such a wide range of variables it’s important to ensure your child is receiving this to ensure healthy development.

How to Ensure Your Child Gets Enough Vitamin D

The simple answer is don’t rely on sunlight alone!

Ensure your child’s weekly diet includes:

• Oily fish, red meat or egg yolks.

• Fat spreads fortified with vitamin D.

• Vegan milk alternatives fortified with vitamin D such as almond, soy or rice.

• Or fortified breakfast cereals - such as Weetabix, Cornflakes, Rice Krispies and Shreddies.

Please note in the UK, cows' milk is generally not a good source of vitamin D because it is not fortified, as it is in some other countries like the USA.

Another source of vitamin D is dietary supplements! But please speak to your health visitor or GP before giving your little one any dietary supplements.

The NHS recommends that babies from birth to 1 year of age should have a daily supplement of 8.5 to 10 micrograms of vitamin D throughout the year if they are:

• Breastfed,

• Formula-fed and are having less than 500ml of infant formula a day (as infant formula is already fortified with vitamin D).

Children aged 1 to 4 years old should be given a daily supplement containing 10 micrograms of vitamin D throughout the year.

You can buy vitamin D supplements or vitamin drops containing vitamin D (just make sure they’re labelled for under 5s) at most pharmacies and supermarkets.

Women and children who qualify for the Healthy Start Scheme can also get free supplements containing vitamin D – click here to learn more.

Ensuring Your Child’s Healthy Development With Vitamin D

To summarise, Vitamin D plays a crucial role in your child’s growth, helping to build strong bones, teeth, and more.

With the high prevalence of Vitamin D deficiency in the UK, it’s important to take steps to ensure your little one is getting enough of this vital nutrient.

By combining a balanced diet rich in Vitamin D, safe sun exposure, and the recommended supplements, you can help protect your child from the risks associated with deficiency.

Remember, each child is unique so speak to your health visitor, nursery manager or GP for advice or if you have any concerns.

Additional Resources For More Info

Click here for Holland & Barrett’s Guide to Vitamin D for children and babies.

Click here to the NHS vitamins for children guide

Click here for the NHS Vegan nutrition guideline.

FAQs

How much Vitamin D does my child need daily?

Children from the age of 1 year and adults need 10 micrograms (mcg) of vitamin D a day. This includes pregnant and breastfeeding women, and people at risk of vitamin D deficiency.

Babies up to the age of 1 year need 8.5 to 10 micrograms of vitamin D a day.

Can my child get enough Vitamin D from sunlight alone?

While sunlight is a primary source of Vitamin D, it can be challenging to get enough in the UK, especially during the winter months.

Factors like weather, skin coverage, and the use of sunscreen can limit exposure. It’s important to combine sunlight with dietary sources and supplements.

What are the signs of Vitamin D deficiency in children?

Symptoms of Vitamin D deficiency can include tiredness, muscle weakness, bone pain, and in severe cases, skeletal deformities like bowed legs, known as rickets.

If you notice any of these signs, contact your GP.

Are there any risks associated with giving my child too much Vitamin D?

Yes, too much Vitamin D can lead to hypercalcemia, a condition where there is too much calcium in the blood.

This can cause nausea, vomiting, and kidney problems.

Always stick to the recommended dosage, and consult your GP if you're unsure.

Can I rely on fortified foods alone to meet my child’s Vitamin D needs?

Fortified foods can help, but they might not provide enough Vitamin D on their own, especially during the winter months.

It’s usually recommended to combine fortified foods with supplements and safe sunlight exposure to ensure adequate levels.

What should I do if my child refuses to take Vitamin D supplements?

If your child resists taking supplements, try mixing them with food or drinks, or consider using a different form, such as chewable tablets or liquid drops.

Consult your GP for alternative options if needed.