The Sunshine Vitamin
Vitamin D has been a hot topic for many years now and more notably in recent times thanks to this essential nutrient's impact on our immune system and potential links with the COVID19 pandemic (1). Government recommendations state that we should supplement the ‘Sunshine Vitamin’ during the autumn and winter months when we are exposed to less sun, but some health professionals are questioning how we can be sure we’re getting enough?
The widespread effects on our body
Our understanding of how Vitamin D actually supports our health has expanded from only considering its impacts on our bone health. In fact, every cell in your body has a receptor for D, which makes it more like a hormone than a vitamin and demonstrates just how important this key nutrient is for almost every bodily system.
We now know that achieving and maintaining optimal levels plays key roles in musculoskeletal, cardiovascular, mood and brain health, immune regulation, insulin function, inflammatory problems and risks in cancer and autoimmune diseases.
A new study (2) has also come to light that indicates low vitamin D causes chronic inflammation. This could be a huge issue when you consider a governmental report found that around 25% of adults and teenagers in the UK have low levels of vitamin D (3), putting them at risk of vitamin D deficiency. The good news is that boosting vitamin D levels could reduce inflammation.
Is the summer sun enough?
Vitamin D is pretty unique to most other essential nutrients in that our major source doesn’t come from the food we eat but actually our star, the sun. When our skin comes into contact with UVB rays, absorbing the light through receptors, it creates a chemical reaction resulting in the production of vitamin D. In terms of dosage, it is thought that when our bare skin is exposed for 20-30mins it can make up to 10,000 IU vitamin D in one sitting.
When it comes to exposure, we can run into a few confusing issues. It is recommended that during April all the way up to the end of September, we expose ourselves to the sun for short periods (around 30 minutes) with no sunscreen, and forearms, hands and lower legs exposed.The optimum time for the best sunlight for vitamin D production is considered somewhere between 11am and 3pm. Contrary to this, we are also told to stay away from ‘harmful rays from the midday sun’ to prevent damage and reduce our skin cancer risk - so what should we actually do?
It seems that if you spend regular time outside, perhaps exercising or gardening and don’t use sunscreen for every minute of the day then you may be getting enough sunlight to keep your vitamin D topped up. However the norm appears to be that most people still drive to their job, work indoors and only really see the sun at the weekend (baring in mind your body can’t make vitamin D from sun rays through a window because the UVB rays can’t get through the glass) and therefore are possibly not getting as much exposure as they think.
Who is at higher risk of low Vitamin D?
On top of the issue of getting enough sun, there are some groups of people who need to pay closer attention to their vitamin D levels than others:
- Those who are pregnant or breastfeeding – to help the baby develop well (4)
- Babies and children – to help aid growth and brain development (5)
- Those with darker skin may need to spend longer in the sun to produce adequate amounts of vitamin D (6)
- Vegans/vegetarians may also want to take into account that the foods richest in vitamin D are mainly animal derived (you’ll find Vitamin D3 in our vegan blends to help you get more in your diet for this exact reason!)
Should you supplement vitamin D in the summer?
As with most health related questions, this really depends on each individual and their lifestyle.
Historically there have been concerns with over supplementing, especially if you continue to dose during the summer with a possibility of vitamin D toxicity (7). Vitamin D toxicity causes a calcium build up in the blood which can result in nausea, weakness and kidney issues. However, it is now well established that toxicity is extremely rare and associated with very high, long-term supplemental doses. It is also worth noting that vitamin A and K2 protect against vitamin D toxicity, which highlights once again the importance of a well balanced, nutrient rich diet. Around 10,000iu of Vitamin D supplementation daily for 5 months is considered safe without side effects, but to take it longer than this it is recommended to test your levels.
Testing your vitamin D levels once, or even better, twice per year can give you an excellent idea on when to supplement and how much. You can get your vitamin D levels checked, either through your GP or with a simple finger-prick test that you can easily order online. The best time of year to check this is at the beginning and end of summer. At the beginning of spring/summer, your body will have used it’s stores of vitamin D during the winter months, so it is great to check in to see whether you need a helping hand over those summer months or whether a daily maintenance dose is actually right for you. At the end of summer your Vitamin D levels should be at their highest, as it's the time of year you’re most likely to get enough sun exposure. If they are low at the end of summer this indicates you need to look into why this may be and also adjust your supplementation.
Synergy in nutrients
As with every other nutrient, thinking about Vitamin D alone is not enough; you also need to pay attention to magnesium, vitamin A, and vitamin K2, which work synergistically with vitamin D - ideally through diet and for some people with supplementation. Vitamin D is also a fat-soluble nutrient so ensuring that you are getting enough healthy fats in your diet is key. When supplementing any of the fat soluble vitamins A,D,E + K; you can boost your absorption by taking it with a source of fat - MCT oil anyone?
Safe sun-exposure is also recommended. Spending at least 20 minutes outdoors before applying sunscreen or even moisturisers containing SPF is ideal.