Everything you need to know about vitamin D
Many of us worry that we don’t get enough of it, but what exactly is vitamin D, and what is it good for? Here’s why the vitamin is so uniquely important, and why most of us need more than sunshine to get our fill of it.
What is vitamin D?
Unlike other vitamins we need, vitamin D is considered a steroid hormone. It’s produced from cholesterol when our skin is exposed to direct sunlight outdoors – hence why it’s often branded the ‘sunshine vitamin’.
Why do we need vitamin D?
Vitamin D helps regulate the amount of calcium and phosphate in our bodies: nutrients which are vital for maintaining healthy bones and teeth. Getting adequate levels of vitamin D lowers our risk of developing the bone-thinning disease osteoporosis, and research indicates it helps increase muscular strength, too.
It might be important for other bodily functions, too. A growing body of evidence suggests vitamin D supports our immune function. Some studies suggest taking vitamin D supplements could help reduce the risk of developing type 1 diabetes, lower the chances of dying from cancer, and ease the symptoms of depression – though more research is needed to confirm these links.
What we do know, however, is that a regular source of the sunshine vitamin is essential to maintaining our overall health.
Where do our bodies get vitamin D from?
Chiefly, we get our vitamin D from time spent outdoors in sunlight, but it’s also found in some foods.
Those such as oily fish, red meat and egg yolks are good sources of vitamin D, but some plant-based products – such as breakfast cereals and plant milks – are fortified with it, too.
Despite this, numerous studies demonstrate that many people are still deficient, as we can’t get enough vitamin D from food alone. One large whole egg, for example, contains about 10% of your daily vitamin D needs.
That’s where vitamin D supplements come in. For many people, it is necessary – and recommended by doctors – to take supplements of this essential nutrient in order to reach their recommended daily allowance.
How much vitamin D do we need?
In the UK, adults are advised that they need 10 micrograms (or 400 IU) of vitamin D a day.
This includes pregnant and breast-feeding women, and people at risk of vitamin D deficiency, such as those who don’t often get outside, or who wear clothes that cover up most of their skin.
Am I getting enough?
While it’s hard to tell without medical interventions, such as a blood test, it’s likely you can benefit from adding more into your life – especially during those shorter days – as vitamin D deficiencies are common.
In the UK, it’s thought that one in five adults and one in six children don’t get enough vitamin D.
Should I take Vitamin D as a supplement?
In the UK, the NHS recommends that everyone (including pregnant and breast-feeding women) should consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter months.
Can’t I just get my vitamin D from sunlight?
In summer and spring, your primary source of vitamin D is sunlight. Typically, in the UK, from the start of April until the start of October, this should be, in theory, sufficient for all your vitamin D needs. Since your body can store vitamin D for weeks, sunlight doesn’t only benefit you on the day that you experience it.
However, due to many factors, even in summer, many adults and children still can’t – or don’t – get all they need from their environment alone. If you have a dark skin tone – for example, if you have an African, African-Caribbean or south Asian background – you’ll need to spend longer in the sun to make the same amount of vitamin D as someone with lighter skin. If your lifestyle means you spend a lot of time indoors, you might also be at risk of deficiency.
Plus, the benefits of sunshine-sourced vitamin D can only be reaped when you’re exposed directly – not through sunscreen, a glass window or clothing, for example. Direct exposure to strong sunshine can expose you to other risks, too, such as sunburn.
During the winter months, we’re lucky to get much sunshine at all! However, at this time of year, UK sunlight also doesn’t contain enough UVB radiation for our skins to make vitamin D.
That’s why the NHS advises people to consider a supplement as the darker days approach, or if you are staying indoors during the spring and summer months.
What happens if you don’t get enough vitamin D?
A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain and osteoporosis in adults.
People with low vitamin D levels might also have a greater risk of developing heart disease, type 2 diabetes and autoimmune diseases like arthritis, and deficiency has been linked to lower life expectancy.
Can vitamin D protect against Covid-19?
There’s a lot that we still do not know about coronavirus. While there have been some reports about vitamin D reducing the risk of Covid-19, there is not enough evidence to support taking vitamin D to prevent or treat it. However, it’s thought getting your daily dose of 10 micrograms might generally provide some benefit in reducing risk of acute respiratory tract infections (such as the common cold).
Overall, it’s never a bad time to add more vitamin D to your life!