Vitamin D plays an important role at every stage of life, but especially during periods of rapid growth seen in infants and teenagers as well as during pregnancy and breastfeeding.

This fat soluble vitamin is actually a hormone that is essential for healthy bones, muscles and teeth as it regulates the amount of calcium in our blood.  It also has a powerful effect on our immune systems.

Vitamin D deficiency is common in childhood, especially in infants that are exclusively breastfed beyond 6 months of age (particularly where the maternal vitamin D stores are insufficient) and where babies have not yet been established on a wide range of solid foods.

Older children who have poor dietary intakes and / or limited exposure to sunlight are also at risk.

So, where does one get vitamin D from?

Vitamin D is available in small quantities of certain foods or from the sun.

Dietary sources of vitamin D are limited.  Vitamin D is naturally found in oily fish and eggs, but the amounts are small.  There are a couple of foods that are fortified with small amounts of vitamin D; e.g. some yoghurts and breakfast cereals and all infant formula milks, but it is worth mentioning that plain cow’s milk is not fortified with vitamin D in the UK and in general breast milk contains little Vitamin D (unless the maternal diet is supplemented).

Sunlight is the best natural source of vitamin D, especially as it is impractical to get sufficient amounts of vitamin D from the food we eat.  Vitamin D is made in our skin when we are exposed to sunlight but only during periods and seasons where the sun is high in the sky.  In the UK, it is not possible for everyone to get enough vitamin D through sunlight exposure alone, especially during the winter months (October and March).

Vitamin D also has a close relationship with calcium and although sunshine is the best source of Vitamin D, diet remains the best source of calcium. Extra care should be taken to prevent Vitamin D deficiency in children with limited dietary calcium intakes. Children with allergies or fussy diets, are often at an increased at risk of developing Rickets due to a calcium and or Vitamin D deficiency.

Who is at risk?

The risk factors for vitamin D deficiency in infants and children include:

  • Infants who are exclusively breastfed for longer than 6 months and where weaning onto complimentary food is delayed (even more so in maternal vitamin D deficiency)
  • Pigmented skin
  • Poor dietary intakes with fussy eaters
  • Limited sunlight exposure in older children and adolescents
  • Children with disabilities (which limits their time spent outside)
  • Children taking anticonvulsant treatment
  • Seasonal changes in sunlight potency, latitude and pollution levels
  • Clothing and the use of sunscreen

The Department of Health currently recommends vitamin supplementation (including vitamin D) in the following at-risk groups;

  • All breastfed infants from 6 months of age
  • Breastfed infants from 1 month of age if there is any doubt about the maternal vitamin D status during and after pregnancy
  • Infants older than 6 months that is formula fed and taking less than 500ml of formula milk per day
  • All children between 1 year ad 5 years old
  • Infants or children previously treated for Ricketts or a vitamin D deficiency
  • Fussy eaters or children on restricted diets
  • Children of Asian, African, Afro-Caribbean and Middle Eastern origin
  • Any child with limited exposure to sunlight i.e. covered skin due to cultural reasons or where they confined indoors for extended periods.

As maternal vitamin D deficiency during pregnancy and breastfeeding is the leading cause of vitamin D deficiency in their infants, all mothers should take a vitamin D supplement throughout pregnancy and whilst breastfeeding.

What to know about supplements?

There are two types of Vitamin D:

  • Ergocalciferol (Vitamin D2) a plant product and
  • Colecalciferol (Vitamin D3) obtained from fish or mammals.

Both Vitamin D2 and D3 are equally effective.   Most vitamin D3 sources are acceptable to vegetarians and those adhering to a Halal or Kosher diets as the main commercial source is Lanolin.

How much is needed?

Based on the current available evidence, the recommended dose for healthy term babies, children and teenagers is 400 units. Pregnant and breastfeeding mothers should also take 400 units daily.

Breastfeeding mothers that are not taking any supplements (or is known to have a deficiency), should start their babies on Vitamin D supplements soon after birth.

Healthy term babies, born to a mother who is taking appropriate prenatal and or breastfeeding supplements can wait until one month of age before starting supplements. The recommended dose for babies is 300 – 400 units daily.  For easy conversion; a dose of 10 micrograms of Vitamin D is equal to 400 units.

Some suitable over the counter Vitamin D supplements currently available for infants and children include:


When purchasing a vitamin and mineral supplement, always check the individual product label for suitability or ask your pharmacist.  It is also advised to raise any allergy concerns when purchasing a vitamin and mineral supplement to avoid any adverse reactions.
* Please note that Abidec contains peanut oil and is not safe to use where there is a history of peanut allergy.  In this instance Dalivit is usually recommended.

Bianca Parau

Specialist Paediatric Dietitian

T: 075 003 88108

E: bianca@lavie-nutrition.com

About The Author

Bianca Parau
Paediatric Dietitian

Bianca is an experienced Paediatric Dietitian offering expert advice and guidance to children and their families with a friendly yet professional approach. After graduating from the University of the Free State she started her career in South-Africa. Since relocating to the United Kingdom she's worked at various NHS hospitals and health centers across the country. Currently practicing in the private sector at BUPA Cromwell Hospital, her main interests are weaning, feeding difficulties, gastroenterology, allergies and intolerances, poor weight gain and weight control. She is very passionate about helping infants and children of all ages develop a healthy attitude towards food whilst meeting their nutritional requirements to sustain optimal growth and development. In addition to private consultations, Bianca is a spokesperson for BUPA on nutrition related topics, writes peer reviews as well as articles for various publications.

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