When those gloomy winter nights transition into progressively brighter spring and summer, do you really need to be thinking about vitamin D?
The aptly-named sunshine vitamin is recommended for everyone during winter, as we don’t get as much sun exposure – which our bodies need to make vitamin D.
Do you need to take vitamin D in the summer when the sun is blazing in the sky? We should be ok - right?
Not always, it seems! Discover why getting enough vitamin D is so important and why some of us might be lacking even in summer.
We’ll also discuss why getting the COVID vaccine doesn’t mean you can throw vitamin D to the wayside – it’s still very much an essential vitamin for our overall health.
- What it is
- Signs of deficiency
- When to take supplements
- Vitamin D and the sun
- Vitamin D diet
- Vitamin D supplements
- Vitamin D and COVID-19
What is vitamin D & why is it important?
Also known as cholecalciferol, Vitamin D is a fat-soluble vitamin that our bodies need in order to absorb and use phosphorus and calcium.
Both of these minerals are essential for maintaining strong, healthy bones and teeth, as well as support other body processes like heart and muscle function.1
Vitamin D is also important for:
- Supporting the immune system
- Muscle function
Signs that you're deficient in vitamin D
Vitamin D deficiency in children can result in rickets, whereas adults are put at risk of bone conditions like osteomalacia.2
Other low vitamin D deficiency symptoms include:
- Joint and bone aches
- Growth problems
- Gum disease
How to test your vitamin D levels
Stick with us to learn more about vitamin D and our health, how to test your vitamin D levels and why it is so important.
How to test your vitamin D levels
Should you take vitamin D all year round?
Yes, contrary to popular belief, a good few of us could benefit from taking a vitamin D supplement the whole year-round.
A governmental report found that around 25% of adults and teenagers in the UK have low levels of vitamin D, putting them at risk of vitamin D deficiency.
As food sources of vitamin D are few and far between and we are not always guaranteed a sunny day here in the UK, supplements are considered a safe way to help ensure you have sufficient levels in your body.3
It’s also worth remembering that 90% of the vitamin D we need comes from sunlight, and only 10% comes from diet.4
Some groups of people are specifically recommended to take a vitamin D supplement all year round, including:
- Vegans/vegetarians – as most vitamin D-rich foods are from animals
- Pregnant people – to help the baby develop normally
- Babies and children – to help them grow and develop normally, especially for their little bones!
- Those who spend a lot of time indoors – as they may not be getting adequate sun exposure every day
- Those who get limited sun exposure - for example, those who wear religious coverups like a hijab
- People with dark skin – this is because the melanin doesn’t let the skin absorb as much UV radiation from the sun, especially in the UK
Should you take vitamin D in the summer?
It really depends on each individual and their lifestyle. If you spend time outside in the sun every day without SPF or covering up too much of your skin, you’ll probably be ok.
The same goes for people who eat a lot of vitamin D rich foods like red meat, whole eggs, oily fish and fortified juice/plant milk or breakfast cereals.
However, as we mentioned above, our bodies need a daily dose of vitamin D. Based on The Scientific Advisory Committee on Nutrition, the government have recommended a reference nutrient intake (RNI) of 10 micrograms (ug) or 400 I.U of vitamin D per day, throughout the year, for everyone in the general population aged 4 years and older.5
Not sure what an RNI is? Essentially, this is the dosage that should meet the needs of the general population.
It’s all too easy to go a day here and there without getting some decent sunlight or eating foods with vitamin D during our delightful British summers, so a supplement can be considered a ‘fail-safe’ option.
How long do you need to be in the sun to get vitamin D?
The NHS state that it’s not known exactly how much time we need to spend in the sun to make enough vitamin D.
During April all the way up to the end of September, they recommend going out in the sun for short periods (around 5-30 minutes) with no sunscreen on, and forearms, hands and lower legs exposed.6
The optimum time for good sunlight is considered somewhere between 11am and 3pm – or whenever the sun starts to shine through your window, begging you to get outside for a break!
This should be enough for most people in the UK to make adequate vitamin D every day.
However, those with darker skin, e.g. those of African or south Asian origin will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter-coloured skin.
It can be a little tricky though, as you don’t want to expose your unprotected skin for too long, as this can cause sunburn and increase the risk of skin cancer.
Be sensible about it and get out of the sun or apply sunscreen after you’ve got enough exposure.
P.S: your body can’t make vitamin D from sun rays through a window because the UVB rays your body needs to make vitamin D can’t get through the glass!7
What happens if you don't get Vitamin D from the sun?
The sun provides us with the cheapest and most useful vitamin D, we can’t deny it, but it is not the only way to get enough of the good stuff.
You can also get vitamin D in the following ways:
A vitamin D-rich diet
Although it can seem a little tricky, especially if you have a restrictive diet (yes, we’re looking at you vegans!) anybody can get some of the vitamin D they need from food.
The following foods provide vitamin D:
- Red meat
Fish and seafood
- Oily fish, like salmon8
- Whole eggs (the yolks the important thing!)
- Fortified cow’s milk
- Fortified dairy yoghurt
- Soya milk
- Almond milk
- Fortified vegan yoghurt
- Fortified orange juice
- Fortified breakfast cereal
- Fortified meat substitutes
Vitamin D supplements
Vitamin D supplements are recommended for the majority of people in the UK during the autumn and winter months.
They’re also recommended all year round for some groups of people at risk of low vitamin D, including the over 65s, people with dark skin, and vegans/vegetarians.
Thankfully, there are a few different ways you can take a vitamin D supplement, including:
- Effervescent tablets
And they’re not all made out of the traditional cod liver oil, you can also find vegan and vegetarian tablets made from sheep’s wool, mushrooms grown under UV light and even some fungus!
Handpicked content: 12 of the best vitamin D supplements
Can you be vitamin D deficient in summer?
Yes, you can develop a vitamin D deficiency at any time of the year, including those balmy sunny summer days! This can be for a number of reasons, including:
- Using SPF ALL of the time – you need to have a break if that’s possible for you to allow your body to make vitamin D – 20 minutes or so without sun protection should be ok!
- Covering up – sunlight needs to hit your exposed skin, which means no clothing or SPF can be blocking it. Rolling up the sleeves is often recommended, but some people won’t feel comfortable doing this in public – so try and do it in private if this is the case
- Having darker skin – people with darker skin have a harder time absorbing vitamin D when compared to those with light skin, so they need to spend longer in the sun to do so9
Why is my vitamin D low in the summer?
The same things we mentioned that can cause a deficiency of vitamin D in summer are often the same things that cause low vitamin D too.
Is it ok to take vitamin D all year?
Yes, so it’s perfectly fine to take vitamin D all year for most people, as based on The Scientific Advisory Committee on Nutrition guidance that is recommended by the government.
If you are taking medications or have underlying conditions, it’s always best to check with your GP before you start taking daily supplements, so bear that in mind.
Link between vitamin D and COVID19
As a lot of us spent more time indoors than usual due to COVID-19 restrictions, keeping topped up in vitamin D was considered a high priority.
This is because we would have been getting much less sun than usual and the fact that vitamin D can support our immune systems.
But we’re allowed out more now, a lot of people are vaccinated, and everything seems a little more normal, so should we still prioritise vitamin D supplementation?
That’s for you to judge – do you think you’re getting enough sunlight on your bare skin and eating enough vitamin D foods?
If yes – good for you! You probably don’t need to supplement in the sunnier months.
If not, a supplement could provide you with that peace of mind.
You may have also seen some reports about vitamin D reducing the risk of COVID-19 (coronavirus).
However, while there are numerous trials currently taking place to see if there is a link between the two, there is currently not enough evidence that taking vitamin D can prevent or treat COVID-19.10,11,12
I’ve had the vaccine - do I need to worry about vitamin D?
Vitamin D and the vaccine don’t really have anything to do with one another, they are two sperate entities that can help support our immune systems.
What else vitamin D can protect you from?
Vitamin D helps us to maintain a healthy immune system.13
It also helps protect our muscles, bones and teeth.14
What the experts say on vitamin D post- COVID jab and during the summer
"Vitamin D is a really important nutrient for the maintenance of normal bone health and normal functioning of the immune system", says H&B nutritionist Emily Rollason.
"As it’s more difficult to get this from your diet, it may be wise for some people to supplement throughout the summer, as well as the winter months.
"Particularly if you have a darker skin tone, wear sunscreen often or tend to cover large areas of your body when heading out into the sun, as we would be less likely to be able to synthesise Vitamin D from sun exposure in these circumstances."
Last updated: 8 September 2022