What is Vitamin D and why do we need it?

What is Vitamin D and why do we need it?

Vitamin D has got something to do with the sun and oily fish – right? Well, yes, but that’s not all. It’s actually pretty important for your body, because it acts like a hormone, and helps keep bones, teeth and muscles healthy – including your heart.

What’s more, it’s estimated that 1 in 5 Brits have low vitamin D levels. So, it’s probably important to know what it is, what it does, and what to look out for…

What is vitamin D and why do we need it?

Vitamin D helps our bodies absorb and regulate calcium and phosphorus – nutrients which are both critical for maintaining healthy bones, healthy hearts, and healthy immune systems.

It supports our ability to heal from illnesses and injuries - and is even thought to reduce cancer cell growth.

How do we get vitamin D?

Our bodies create vitamin D from direct sunlight on our skin, which is pretty clever. However, given the British weather and our distance from the equator, the NHS warns that between October and March we don’t make enough vitamin D through sunlight.

Vitamin D can also be found in food, but it can be quite hard to eat enough of the right foods to get all the Vitamin D you need from your diet.

What foods are a good source of vitamin D?

Vitamin D rich foods include things like oily fish, like salmon, mackerel or sardines, red meat, liver and egg yolks. There’s also lots of fortified foods on the market – including breakfast cereals, spreads, and infant formulas.

How much vitamin D do I actually need?

According to the NHS, children over 1 year and adults need 10 micrograms of vitamin D a day. Babies need 8.5 to 10 micrograms a day, but that might not mean very much to most people.

Do I need to take a vitamin D supplement?

There are people who are more at risk of vitamin D deficiency than others, for instance those who aren’t outdoors very much, people who wear high factor sun cream all the time, older people, and those with darker skin or a higher BMI. People taking certain medications or with certain liver and kidney problems may also not produce enough vitamin D.

Having said that, it’s thought that most people in the UK probably do need to take a vitamin D supplement over the Winter months, because the sun isn’t strong enough and we’re all wearing our woollies! The NHS reckons 1 in 5 Brits aren’t getting enough vitamin D between September and March.

How much vitamin D should I take?

If you do want to take a vitamin D supplement, you should take a daily dose of 10 micrograms. Ask your pharmacist for help choosing a supplement if you find the labels too confusing!

Should I just spend more time in the sun to get my Vitamin D?

Yes and no. Getting sunshine every day is good, but we all know that too much sun is bad for our skin and can increase your risk of skin cancer.

Between Spring and Autumn just being out and about with arms or legs uncovered for short periods without sunscreen should be enough for you to make all the vitamin D you need. For longer periods it’s important to wear an SPF sunscreen to protect your skin.

Exactly how long you need in the sun to make vitamin D will depend on your skin – people with darker skin will need longer to produce the same amount of vitamin D than somebody who has lighter skin.

Remember, you can’t make vitamin D via sun through a window, because the glass blocks ultraviolet B (UVB) rays, which are the ones you need to make the vitamin D.

What happens if you don’t get enough vitamin D?

A lack of vitamin D can lead to bone problems, most famously and historically rickets in children, and bone pain or muscle problems in adults.

What are the symptoms of vitamin D deficiency?


Feeling tired all the time seems like it’s a symptom of everything, but it’s not one you should ignore.

Our GP in residence Dr Faye Gallagher explains: “Believe it or not it’s NOT normal to feel tired all the time without an explanation, and it’s really important to talk to your GP if you’ve been feeling fatigue for several weeks, without getting relief from taking rest. I promise we won’t think you’re wasting our time, and there’s lots we can do to help. Testing for vitamin D deficiency is just one example.”

Muscle and bone pain

It’s very difficult to pinpoint the cause of muscle and bone pain, but we know a lack of vitamin D can sometimes be a factor - and that supplements can sometimes help.

Dr Gallagher says: “If you’ve got unexplained muscle pain, for instance having difficulty climbing stairs or walking with a waddle when you’ve not even been hitting the gym, it’s worth thinking about vitamin D.

“Lack of Vitamin D can affect calcium absorption which can increase your risk of osteoporosis (thinning of the bones). Weak bones that break easily are a sign of longer-term vitamin D deficiency, and that’s something we often see in older people, for example, who find it much harder to make vitamin D naturally.”

Not getting better as quickly as you used to

If your body isn’t healing wounds after an injury as quickly as it used to, or if you’re finding it’s taking you longer to get better from mild illnesses you used to bounce back from, it might not just be a sign of age…

“Vitamin D deficiency can stop your body from effectively fighting off illnesses,” explains Dr Gallagher. “If you find you’ve been picking up momre viral infections recently, or you’ve been struggling to get over them compared to normal, it might be worth mentioning it to your GP.”

Hair loss

Not necessarily a common symptom but one that’s been increasingly linked to vitamin D is hair loss. Dr Gallagher says: “Hair loss can sometimes have a connection to vitamin D, and if it’s something you’re worried about taking a vitamin D supplement is a good place to start. It’s also a really important vitamin for healthy nails, skin and heart health, too.”


Low levels of vitamin D can cause low mood in both adults and children. Dr Gallagher says: “If you’ve been experiencing depression or low mood over a period of weeks, it’s time to talk to someone. There’s so much your GP can do to support you, and first on their list will be checking for physical reasons that your mental health is suffering.

“Don’t forget that some Equipsme members will also have access to the stress support line, and that’s another great resource for people who are struggling.”

Poor growth and tooth decay in children

Children with a severe vitamin D deficiency may have soft skull or leg bones – some very serious even walking with bowed legs, commonly known as rickets. But less severe symptoms can include poor growth, a reluctance to walk, and tooth decay.

Dr Gallagher adds: “Your health visitor and GP will help you keep an eye on your child’s growth, but if you notice any symptoms that worry you it’s worth bringing them up. Remember that formula is reinforced with vitamin D, and if you’re breastfeeding the advice is to take a vitamin D supplement anyway. If your own vitamin D levels are good, your baby will be getting all that good stuff from you.”

What happens if you get too much vitamin D?

Too much of anything is never a good thing – and taking too many vitamin D supplements could cause a build-up of calcium in the body, which might damage bones, hearts, and kidneys. Ask a Dr before you take over the recommended daily 10 micrograms.

The good news is you can’t overdose on vitamin D through sunlight – but you can burn! So, make sure you cover up or put on sunscreen before you go red.

How do I know if I need to take more vitamin D?

You can find out if you’re making enough vitamin D with a simple blood test.

You can ask your GP for the test, or all Equipsme members (except for those on GP+) can get an annual vitamin D test to do at home through our health check partners Thriva.

Thriva will have emailed you to order a test when your plan started or renewed. If you missed it, just email us at members@equipsme.com and we’ll sort it out for you.

How do I do the test?

Thriva will send you a pack through the post, with full instructions to help you do your finger-prick test from the comfort of our own home. You then pack it up, send it back through the post – and wait about a week for an email to access your online.

It’s quick, it’s easy, it’s convenient, and it really can help you stay healthy.

What do I do if I’ve still got vitamin D questions?

Find out more about vitamin D on the NHS website

Find out more about vitamin D on the Heart UK website

Find out more about vitamin D and breastfeeding on the Breasting Network website

Or talk to your own GP or make an appointment with one of Equipsme’s 24/7 GPs for a chat.