What exactly is vitamin D?
Commonly known as the sunshine vitamin, vitamin D is important for regulating the amount of calcium and phosphate we have in our bodies. These are the nutrients our body uses to keep our bones, teeth and muscles healthy. Typically, during the sunnier months, we get most of our vitamin D from spending time outdoors.
‘One of the ways our bodies manufacture vitamin D is through exposure to sunlight,’ says Dr McClymont. ‘But recently lockdowns, home working and shielding may all have led to us spending less time in the great outdoors than we’d like. And now we're in winter, it’s even more important to think about vitamin D and the other sources we can get it from.’
What does it mean to have a vitamin D deficiency?
A vitamin D deficiency is, simply, when you don’t have enough vitamin D in your body. In winter and when we're spending more time indoors, we're not able to get all the vitamin D we need from sunlight and we may need to top it up.
Some people will never get high enough vitamin D levels from sunlight as they don’t get enough exposure to the sun. In these cases, its recommended to take a daily vitamin D supplement all year round.
What are the symptoms of a vitamin D deficiency?
Usually, there are no symptoms of a vitamin D deficiency. If they are present the signs are often subtle, but some people may notice:
- Getting illnesses or infections more often
- Feeling tired or fatigued
- Hair loss
- Muscle pain
- Bone and/or lower back pain
- Depression or low mood
- Wounds that heal slowly following surgery, infection or injury
Vitamin D deficiency can also lead to bone density loss, which makes bones more fragile and increases the risk of fractures after a fall.
'The vitamin plays a vital role in keeping our immune system working as it should, so if you’re finding yourself frequently feeling under the weather or battling a cold, it might be down to a lack of vitamin D,' says Dr McClymont.
Who’s at risk of low vitamin D?
- People who are not often outdoors, for example, those who have to shield or live in a care home
- People who cover a lot of their skin when outdoors
- People with darker skin, for example those who are Black or Asian
- People following a plant-based diet, as a lot of food that naturally has vitamin D is fish, red meat and eggs
How do I prevent a vitamin D deficiency?
Thankfully, it’s relatively easy to maintain good vitamin D levels. According to NHS guidelines, babies up to 1 year of age need between 8.5-10mcg of vitamin a day, while children between 1 and 4 should aim for 10mcg a day.
Adults should supplement with 10mcg vitamin D a day during the winter months. Supplements are available from nearly all pharmacies and are available in a range of doses.
For a mild vitamin D deficiency, it may be enough to just take the recommended 10mcg vitamin D a day. More severe deficiencies may require higher doses of vitamin D – but always talk to a pharmacist or GP if you’re unsure.
‘Although getting enough vitamin D is important, it’s also crucial to remember adequate sunscreen to protect against the damaging effects of UV radiation on the skin. People who wear sunscreen can still manufacture enough vitamin D in their skin, with studies finding no association between sunscreen use and vitamin D deficiency. So there’s no reason to avoid it to increase your vitamin D levels, even when it's not summer’ says Dr McClymont.
What are good sources of vitamin D?
- Oily fish like salmon, mackerel and sardines
- Red meat
- Egg yolks
- Fortified foods like breakfast cereals
- Dietary supplements
‘In some countries cow’s milk is fortified with vitamin D, which can provide a good source of intake. But in the UK this is not standard practice,' explains Dr McClymont. 'Although you may be able to find a small minority of cow’s milk brands that have extra vitamin D included, it's best to concentrate on the other dietary sources above if you’re looking to increase your levels.'
How do I treat a vitamin D deficiency?
There are three ways to help a vitamin D deficiency:
- Try to get more sun exposure – around 15-20 minutes, 3 times a week is enough
- Eat vitamin D-rich foods (listed above)
- Take a vitamin D supplement
If you’re worried about low vitamin D levels or you’re experiencing symptoms of a vitamin D deficiency, it’s best to get it checked out by a doctor.
What about vitamin D and Covid-19?
Throughout the pandemic there’s been a lot of debate about whether vitamin D may be beneficial in those with Covid-19.
'Research has shown that those most at risk from Covid-19 – older adults, care home residents and Black, Asian and minority ethnic groups – are also those statistically more likely to have a vitamin D deficiency,' explains Dr McClymont.
'But there’s been no proven link between the two so far, and a large scale review of vitamin D in the context of Covid-19 concluded there was insufficient evidence to suggest using vitamin D to prevent or treat Covid-19.'
'It’s the government’s advice that everyone in the UK supplements with a low dose of vitamin D during the autumn and winter months, when there’s poor exposure to sunlight, especially those who are vulnerable.’