Vitamin D is essential for our wellbeing and bone health and it's crucial that growing babies and children get enough.
But it can be confusing knowing whether a supplement is needed, and if so how much should be taken. There's also the bewildering choice of options - should you go for tablets, gummies or drops?
Vitamin D is also known as the 'sunshine vitamin' because the best source comes from the action of sunlight on our skin. We also get some vitamin D from food (see below to find out which foods).
Dr Yiannis says: 'However, it's difficult for babies and children to get enough vitamin D from the sun, especially in the winter, and it's also hard to get enough from their diet.'
This is why vitamin D is recommended - either through formula milk or with a separate supplement. The amount of vitamin D required and for how long depends on the child's age.
Under six months of age, the following guidelines apply:
Breastfed babies should be given a daily vitamin D supplement from birth, regardless of whether you're taking a supplement containing vitamin D yourself.
Bottle-fed babieswho are having more than 500ml (about a pint) of infant formula a day shouldn't be given vitamin supplements. This is because formula is fortified with vitamin D and other nutrients.
If you are both bottle-feeding and breastfeeding, don't supplement unless the formula intake falls below 500ml. If you have any questions speak to your GP, health visitor or pharmacist.
Birth to one year: The Royal College of Paediatrics and Child Health says infants aged from birth to one year should be given vitamin D supplementation of 8.5-10mcg (micrograms) - equivalent to 400IU (International Units) - daily and all year round.
One to five years of age: Children should take a daily vitamin D supplement of 10mcg, which is the same dosage adults take. The NHS also recommends that they take vitamins A and C from the age of six months to five years of age. They should take this all year round.
Over five years of age: The government advises everyone to take a 10mcg vitamin D supplement during the winter months (defined by the National Osteoporosis Society as between the end of September and the beginning of April).
Professor Cyrus Cooper says: 'Children have bones that are growing rapidly and need a plentiful supply of vitamin D and calcium to support this.
'Winter months are important to cover, but evidence suggests that supplements of 400IU may be beneficial throughout the year.'
Government guidance is just for the winter, but there's no harm in giving this dose to children in the spring and autumn months too.
There are a range of symptoms in babies and children that indicate too little vitamin D, including:
These symptoms arise because vitamin D is vital for helping our bodies to absorb calcium and phosphorus, which are essential for healthy bones, teeth and muscles.
Although severe vitamin D deficiency is rare, Professor Cooper explains: 'Insufficiency due to inadequate sunlight exposure or diet is much more common and widespread.'
So supplements can be important to help maintain adequate circulating levels of vitamin D and to optimise bone growth.
There's lots of choice when it comes to vitamin D, including tablets, oral sprays, drops, effervescent tablets and even gummies.
The thing to know is that they are all as effective as each other when it comes to delivering a vitamin D dose to your little one.
For example, a 2020 metastudy published in the journal Nutrients looked at 9,759 randomised controlled trials and found no evidence that vitamin D is delivered more effectively by oral spray than any other mode of delivery.
Dr Yiannis says: 'The best supplement is the one your child is happy to take. If they don't like the taste of one, then try another. Whatever your preferred supplement, choose one with vitamin D3, which is the most readily absorbed.'
Always check the manufacturer's instructions before giving a supplement to your child.
Drops: Ideal for babies and toddlers. The options for taking them include putting them straight onto their tongue, onto your nipple if you are breastfeeding or into formula, expressed milk, juice or a small amount of food.
Spray: A good option for kids who don't like tablets or aren't able to swallow them. These are typically flavoured for palatability.
Gummies: These may appeal to children who are picky eaters. Keep out of reach when not being administered - they aren't sweets.
Tablet: Ideal for older children such as those over 12, who may be more capable of swallowing tablets. This can be a cost-effective option, too, if you opt for a generic or own brand.
Effervescent tablets:These can generally be used by kids who are 12 and older. The , the Association of UK Dietitians, says that fizzy supplements contain around a gram of salt per tablet so you might want to consider an alternative, especially if you've been advised to limit your salt intake.
Talk to your pharmacist about which supplement to buy. This will help to prevent you doubling up on certain ingredients, which can happen if you are considering multiple supplements such as a multivitamin plus cod liver oil.
The cost can be greater for baby and children formulations than adult ones, especially for gummies, which can cost around 24p per day (compared with14p for an adult version).
However, if you know your kids will take them rather than spit them out or even refuse to take a supplement at all, they could be worth the extra cost.
In general the price of vitamin D supplements for adults ranges from 3p to 30p per dose, the cheapest being own-brand vitamin D tablets from supermarkets and pharmacies (less than 3p per daily dose).
Sprays for children are around the same as adult ones (around 7p) as are drops (around 17p).
Older children (those over 12) can use tablets, bringing the cost in line with that for adults, but always check the packaging before giving them to your child.
Look for offers, such as three-for-two, to help bring the overall price down.
In some instances, you won't have to pay for a supplement. Alison Morton, acting executive director of the Institute of Health Visiting, says: 'Women and children who qualify for the Healthy Start scheme can get free supplements containing vitamin D.'
Adding these foods to your diet will help to increase your vitamin D intake:
However it's hard to reach your daily needs through diet alone.
Professor Cooper says: 'Oily fish is high in vitamin D, but sunlight exposure - outdoor activity for a couple of hours daily - is more effective.'
More than 50% of people of Asian ancestry in the UK are severely deficient in vitamin D, plus one third of people of Black African ancestry in the UK also have high levels of vitamin D deficiency because dark skin absorbs less UV radiation from the sun.
This type of deficiency is also seen in children from these ethnic groups. A 2020 University of Birmingham study reported in the journal Clinical Nutrition found that one third of all babies and half of Black, Asian and minority ethnic (BAME) babies are vitamin D deficient.
Research in 2019 reported in the journal Archive of Diseases in Childhood looked at the UK national incidence of nutritional rickets in under 16s and although it found fewer cases than expected, it found that serious complications were more likely in Black and South-Asian children under five years.
It also found that both vitamin D and calcium deficiency had a key part to play in these situations. This makes it even more important for babies and children in these ethnic groups to be given vitamin D supplementation.
Professor Cooper says: 'BAME children are at greater risk of vitamin D insufficiency and are therefore more likely to benefit from year-long supplementation.'
Talk to your midwife, health visitor or medical team for more information if you are concerned about the vitamin D status of you or your child.
The NHS says there have been some reports about vitamin D reducing the risk of coronavirus (COVID-19) but that 'there is currently not enough evidence to support taking vitamin D to prevent or treat coronavirus.'
However, in relation to pregnancy and birth, we do know that 55% of pregnant women admitted to hospital with COVID-19 are from a BAME background, even though they only make up a quarter of the births in England and Wales.
We also know that Asian women are four times more likely than white women to be admitted to hospital with COVID-19 during pregnancy, while Black women are eight times more likely.
As a result, the NHS is ensuring that hospitals discuss vitamins, supplements and nutrition in pregnancy with all women.
This is because women who are low in vitamin D may be more vulnerable to coronavirus so women with darker skin or those who always cover their skin when outside may be at particular risk of vitamin D deficiency and should therefore consider taking a daily vitamin D supplement all year round.
As of December 2020, the UK government started to supply free vitamin D supplements in the winter months to those most at risk of coronavirus. People on the clinically extremely vulnerable list will be contacted and can opt for a supply delivered to their door.