When the skin is exposed to ultraviolet B (UVB) rays, the body produces vitamin D. Sunscreens block UVB rays as they cause sunburns and skin cancer. It is easy to make a connection between the two.
Yes, the use of sunscreen could theoretically lead to a vitamin D deficiency, but it isn’t going to happen.
A study published in the British Journal of Dermatology found that sunscreen does not block enough UVB rays to prevent healthy vitamin D production. According to lead author Prof. Antony Young, of King’s College London, “Our study, during a week of perfect weather in Tenerife, showed that sunscreens, even when used optimally to prevent sunburn, allowed excellent vitamin D synthesis.”
The findings could be because sunscreens don’t block all UVB rays. Even SPF 50 allows about 2% of the UVB rays to pass through. Another factor could be that no sunscreen application is perfect. Coverage and reapplication can be spotty.
In short, don’t sacrifice proper sun protection to prevent deficiencies. You’ll get plenty of vitamin D even if completely coated in sunscreen.
If you are still concerned, add wild salmon to your diet. It is naturally high in vitamin D.