What is Vitamin D and why is it important?

A question that is often asked is “does my child need to be taking a vitamin supplement?” Whilst some children may benefit from additional supplementation of certain vitamins and minerals (which can be guided by a healthcare professional) alongside their diet there is one vitamin that all infants and children require and that is Vitamin D. 

In this blog you will find out: 

• What is Vitamin D and why is it important 
• When to supplement with Vitamin D
• How to choose the right supplement
• Dietary sources of Vitamin D 

1. What is Vitamin D and why is it important

Vitamin D is an essential fat soluble vitamin. It has a vital role in supporting the balance of calcium and phosphate in the body and so is essential for healthy muscles, bones and teeth. It also supports the healthy functioning of the immune system. Unlike other vitamins, dietary sources of Vitamin D are limited, so the majority of our Vitamin D comes from sunlight exposure on the skin (1).  In the UK sun exposure is limited through the Autumn and Winter months so our bodies can not produce enough Vitamin D. 

In the UK, 1 in 5 children (20%) have Vitamin D levels lower than the UK government recommendations. Prolonged  low levels of Vitamin D can lead to bone conditions such as rickets (1)

The amount of Vitamin D the skin produces can vary and certain factors can impact on a child’s risk of Vitamin D deficiency, these include:

• Children who have low or no exposure to the sun
• Children who usually wear clothing that covers most of their skin when they are outdoors 
• Children who have darker skin pigmentation
• Children who take medication that can interfere with Vitamin D absorption e.g. antiepileptic medication 
• Children with moderate to severe eczema – whilst not yet in clinical guidelines, clinical practice and experience has shown that many children with eczema have low vitamin D levels and would benefit from supplementation. 
• Sunscreen use- though as most people don’t apply sunscreen at the recommended concentration or to all exposed areas of skin, normal usage of sunscreen doesn’t generally prevent Vitamin D production. 

2. When to supplement with Vitamin D

Limited dietary source and sun exposure means that all children need to supplement with Vitamin D at some point but  when and how much depends on factors such as how a child is being fed e.g. breastmilk or formula milk and their age. 

Some important points to note: 

• Formula milk contains Vitamin D and so supplementation will depend on if and how much formula milk your baby consumes. 
• If you’re a breastfeeding mum, it is also recommended you also supplement daily with 10ug Vitamin D
• It is possible to give too much Vitamin D, though Vitamin D toxicity is rare, so it’s important to give the recommended doses to babies and children. This is particularly important for fat-soluble Vitamins like Vitamin D and A, as they are stored rather than excreted (removed) by the body. 

How much to supplement: 

3. How to choose a Vitamin D supplement: 

• Vitamin D3 is generally preferred  as it is more effective and raising and maintaining Vitamin D levels in the body than Vitamin D2  
• Choose from which your child can take safely, easily and consistently. For babies Vitamin D will mostly come in the form of liquid drops or a spray and for older children gummies and chewable tablets are also available.
• Make sure it contains enough Vitamin D- check the label and ensure that the dose is 10ug (400 international units IU) per dose – some multivitamins do not contain the recommended amount of vitamin D and some contain far more than the recommended dose for children,  so it’s always important to check!
• For children age 6 months – 4 years Vitamin A supplementation is also recommended alongside Vitamin D supplementation as Vitamin A deficiency can also be common in this group. 

Dietary sources of Vitamin D 

Dietary sources of Vitamin D are limited so even if you do include the following foods in your child’s diet  the supplementation above  is still recommended.

• Oily fish e.g. salmon, mackerel, sardines
• Eggs
• Red meat and offal e.g. liver
• Fortified milk e.g. Arla Big Milk or plant-based milk alternatives 
• Mushrooms – leaving them in the sun before cooking increases their Vitamin D content.

References: 

1. NICE Vitamin D deficiency in children https://cks.nice.org.uk/topics/vitamin-d-deficiency-in-children/
2. NHS Vitamin D https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
3. SACN Vitamin D and https://www.gov.uk/government/publications/sacn-vitamin-d-and-health-reportealth