How Does the Sun Help Make Vitamin D3?

Natural Vitamin D3 production begins with the synthesis of a protein present throughout your skin.

The Sun’s ultraviolet B (UVB) rays interact with this converting it into a D vitamin called preD3.

Once it has been converted into vitamin D3, our body can use it.

In this post, we take a closer look at how that conversion happens.

You will also discover some common warning signs to look out for that may indicate a Vitamin D3 deficiency along with a few associated diseases.

I finish by giving you a few ideas around some vitamin D3 rich foods you can easily incorporate into your everyday diet.

Below I have highlighted the important bits for you, just in case your schedule is tight.

Click the link you want to start with or by all means, continue on.

You Need Sunshine To Make Vitamin D3

Vitamin D3 is crucial to maintaining normal blood levels of calcium and phosphorus, helping develop and strengthen bones.

D3 aids the development of teeth, and it is thought that supplements can also reduce the number of non-spinal fractures.

your-body-works-with-the-suns-rays-to-produce-vitamin-D3 Many people do not get enough of this vital vitamin because it cannot make sufficient amounts needed to sustain a healthy immune system.

This is especially if you live in northern climates or do not spend much time in the Sun.

Your body uses sunlight to make Vitamin D3 naturally; therefore, you need to be getting enough sun all year round.

Not having access to sunshine all year round or not spending enough time out in it, may indicate you already have a significant shortfall in your vitamin D stores.

Does Skin Color Have An Impact On the Ability to Produce Vitamin D3 Naturally?

Yes, it does.

One of the biggest drawbacks in producing vitamin D3 naturally is skin tone.

Skin that is usually darker in hotter climates contains a pigment called Melanin which gives skin a beautiful rich colour.

Melanin absorbs the suns ultraviolet rays that initiate vitamin D synthesis, significantly inhibiting the skins’ ability to produce Vitamin D3.

The melanin makes it almost impossible for people with darker skin tones to produce enough D3 from synthesis alone.

Skin Colour Makes No Difference

However, skin colour or the lack of melanin in your skin bears no significance in countries that can go without sunshine for up to six months a year.

If you live in the Northern Hemisphere, the days are shorter and the nights longer in winter.

It is impossible for you or anyone else for that matter to produce enough vitamin D3 naturally through sunlight alone.

Vitamin D3 Deficiency & Chronic Illnesses

Vitamin deficiency can lead to various ailments, most visually and most notably are the bent limbs and weak bones characteristic of Rickets.

Rickets is a rare disease that causes the bones to become soft and bend. Children, especially children of colour, are at higher risk of getting rickets.

In adults, severe vitamin D deficiency leads to Osteomalacia, a disease that causes weak bones, bone pain, and muscle weakness.

Vitamin D3 is one of the essential vitamins we need and is most likely the most deficient.

However, more research needs to be done before fully understanding the effects of vitamin D on these conditions.

How Does Synthesis Take Place?

A 1980 study by M. F. Holick and colleagues recorded this process that used rat skin as a human skin model.

Vitamin D synthesis begins with cholesterol (7-DHC), a protein present throughout the skin but most highly concentrated in the epidermis’s lowest layers.

The Sun’s ultraviolet B radiation penetrates through the skin, converting the 7-DHC into an isomer, the same chemical formula as D3, but different, called preD3.

Vitamin D3 the sunshine vitamin

The final stage, isomerization, converts the preD3 into vitamin D3, dependent on the temperature within the skin.

The reaction continues, and a protein descriptively named vitamin D binding protein binds to the newly created vitamin D3.

It transports it into the blood via capillaries located where the epidermis meets the lower skin layer of the dermis.

Vitamin D binding protein ensures that synthesis proceeds as efficiently and as efficiently as possible.

Temperatures need to be at or near body temperature for the reaction to proceed, this process continues for around three days, even after sun exposure ends.

Sunscreen & Vitamin D3

Sunscreen can also inhibit the synthesis process in your skin because it blocks both the ultraviolet A (UVA) rays and ultraviolet B (UVB) rays from the sun.

However, wearing sunscreen is a must and should be used at all times whenever you are in the Sun to help protect your skin from sun damage.

You need sunscreen just as much as you need vitamin D3
Wearing sunscreen should be used at all times whenever in the Sun.

Best Food Source

The only plant source that is able to produce Vitamin D3 is mushrooms and only if they have been grown under UV lights to mimic those of the sun.

The idea is that supplements complement your diet, not replace it.

  • fatty fish
  • seafood
  • egg yolk
  • cheese
  • pork chops
  • cod liver oil
  • fortified margarine
  • yoghurts

These are all fantastic sources of vitamin D3.


Please feel free to leave thoughts or comments they are always encouraged and always very much appreciated.

*Please note the information contained in this post is intended for general information and not used as a substitute for healthcare professionals’ expertise and judgment.

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