You probably know that vitamin D comes from the sun and that it's essential for many of our inner workings. It’s difficult to avoid this information nowadays, since the WHO and NHS are encouraging people to use vitamin D supplements throughout the winter.

But do you know how we create vitamin D from the sun, or when is the best time to be out in the sunshine? This big ball of energy provides all living things with the power to grow – including us humans! Pretty incredible, right?

In this blog post, we take a look at how we use sunshine to naturally create vitamin D, as well as the right time for doing so. We’ll also explain alternatives - such as supplements - to get vitamin D into your system safely in the winter days to come.

How Does The Body Produce Vitamin D From Sunlight?

When your skin is exposed to sunshine, it manufactures vitamin D. The sun’s ultraviolet B (UVB) rays interact with a protein called 7-DHC in the skin, converting it into vitamin D3, the active form of vitamin D.

Easy, right? 

In Layman’s terms, sunshine jumpstarts the skin into photochemically transforming cholesterol into vitamin D. We then use vitamin D for a range of essential functions. 


You know how plants use the sun for photosynthesis? They use the sun’s energy to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds which are essential for their growth. 

Well, humans are much the same! We use the sun’s power to convert the protein 7-DHC (cholesterol) into vitamin D, which in turn is used to help us grow.

Without it, much like a plant, “all the leaves are brown and the sky is grey”. 

Of the many things that vitamin D is used for, the absolutely vital ones are:

  • Regulating calcium and phosphate
  • Bone Growth
  • Healthy teeth
  • Metabolism
  • Immunity
  • Brain development
  • Nervous system health

A vitamin D deficiency has a huge range of detrimental and harmful effects on adults and children alike. You can read more about those here.

What Time Of The Day Is Sunlight Good For Your Body? – Vitamin D 

The sun is at its strongest at midday. This is when the ultraviolet B rays are beaming down hardest. And it is those rays which stimulate the skin into photochemically transforming cholesterol into vitamin D efficiently. 

Between late March and September, experts agree that the best time to go out in the sun is between 11am and 3pm, but they also warn that just 15 minutes in the sunshine is sufficient to generate the vitamin D the body needs. Any more than this can lead to too much and then the body must work to reduce an overflow of vitamin D. 

For white-skinned people, exposing your forearms, legs, torso and face for 15 minutes at this time is ideal. For people with black or dark skin, this amount should be a little longer at around 20 minutes. 

Furthermore, there is no evidence to suggest that sun protection creams prevent the skin from doing its job. Even if many sun creams advertise UV protection, they are not 100% effective. And this imperfection is enough for the skin to create vitamin D when exposed to the UV rays from sunshine. Therefore, do use sun creams if you are staying outside for long periods of time. Getting sunburnt is both unpleasant and harmful!

One final thing to note is that glass stops the UVB rays, so sitting by the window in the sunshine may be nice, but it won’t be useful in generating vitamin D. 

What about during the Winter?

Between October and March, getting direct sunshine can be more than challenging, particularly in the UK. And even if there are some days of sunshine, in the winter months, the strength of the sun's UV rays is not enough to stimulate the skin into making Vitamin D. 

Nonetheless, Vitamin D is still an essential part of our everyday wellbeing. And it is especially important to keep levels of vitamin D up over this period, both for our immunity and for our mental health. 

If you’re not planning on moving to the Southern Hemisphere for the next 6 months, health specialists strongly advise that you make sure you’ve got a good supply of vitamin D by using other sources. 

Vitamin D rich foods

  • oily fish - salmon, sardines, herring and mackerel
  • red meat
  • liver
  • egg yolks
  • fortified foods - some fat spreads and cereals

‘Sunshine in a bottle’ supplements

At the wellness-factory, we have a range of supplements to support and promote your overall health and well being. 

We have a variety of easy-to-use and tasty vitamin D supplements which are a super effective way of making sure you are getting the right daily amount.

Our Vegan D3 + K2 drops are orange flavoured and are an excellent way of boosting your immunity and promoting bone and muscle strength.

Another option is our Core Winter Supplement spray; 8 quick sprays under the tongue and you're done.

For children, our little Pharma Kids Vitamin D spray is so simple to use and is a handy and reassuring way of being certain they are getting everything they need to grow strong.

What about sun lamps?

No. Although it is true that the UV rays can stimulate the skin into producing vitamin D, they should only be used by those with vitamin D deficiency, or other ailments, and with a medically trained health professional on hand. Sun lamps increase the risks of skin cancer and are not recommended by doctors. There are easier and more effective ways of getting the Vitamin D you need.