How much Vitamin D Do we produce when exposing our skin to sunlight?

28 April 2021

One of the main ways by which we produce Vitamin D is by exposing our skin to sunlight. Well, this is only partially true because sunlight only is not enough, there must be UVB (ultra-violet B) radiations present as well. UVB radiations are high energy radiations relative to visible light, and UVB participates in the synthesis of a molecule called 7-dehydrocholesterol into Vitamin D3 in the skin. This cutaneous production of Vitamin D3 is however highly dependent on both the amount of UVB present and on your skin type.

Studies have shown that the conversion of 7-dehydrocholesterol into Vitamin D3 is 10 times less efficient for someone with a dark skin (Fitzpatrick type 5) compared to someone with a white skin (Fitzpatrick type 2). This means that black people and those who have a dark skin need to spend a lot more time under the sun in order to produce the same amount of Vitamin D3.

However how much time should you spend under the sun? Is 10 am in the morning the same as 2pm in the afternoon? Is March a good time to synthetize Vitamin D compared to June? These are all important questions which I will answer in coming posts so stay tuned for more.

Healthily yours,


1 thought on “How much Vitamin D Do we produce when exposing our skin to sunlight?”

  1. My skin type is closer to type 5 . Even though I spend lots of time outside, I don’t depend on the sun only to obtain the optimal level. The optimal level for me in my opinion is over 50ng/ml. I can only get that amount from supplements.

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