1. Does sunscreen stop you from absorbing Vitamin D?
Not unless you wear it head-to-toe and re-apply it every two hours every day! And even then, the best sunscreens can't block 100% of the UV spectrum, so some UVB will still get through allowing your body to create Vitamin D.
Vitamin D plays a vital role in many of your body functions, including calcium absorption and bone growth. You can take Vitamin D tablets, but if you can, it’s best to get it naturally (from the sun); the body can easily make its own Vitamin D when exposed to UV rays. Image Vera Nording
“For most people, adequate Vitamin D levels are reached through regular incidental exposure to the sun. When the UV Index is 3 or above (such as during summer), most people maintain adequate Vitamin D levels just by spending a few minutes outdoors on most days of the week.” Cancer Council Australia.
“Sunscreen prevents sunburn by blocking UVB light. Theoretically, that means sunscreen use lowers Vitamin D levels. But as a practical matter, very few people put on enough sunscreen to block all UVB light, or they use sunscreen irregularly, so sunscreen's effects on Vitamin D might not be that important.” Harvard Health
2. Do tanned or dark-skinned people need sunscreen?
There is a big misconception that if you have dark your skin, you don’t need to wear sunscreen.
Why do people think this? Because people with darker skin are more protected from the suns UVB rays, due to higher levels of melanin (melanin acts to diffuse UVB rays and may protect against some sunburns), however, melanin does not protect from UVA. UVA rays are the nasty rays that penetrate deep into the skin (deeper than UVB) damaging your skin's structure, causing premature aging, burning and contributing to skin cancer.
Everyone should use a broad-spectrum sunscreen (SPF 50+).
High levels of melanin still will not protect the skin from extreme sun exposure, such as spending long hours in the sun unprotected or protect people with darker skin against skin cancer.
3. You don’t need to wear sunscreen when it’s cloudy.
Clouds block as little as 20% of UV rays.
4. Don’t be fooled by buzz words ‘natural & organic’.
Let's break it down, 'natural' sunscreen is a term used by many when talking about zinc or titanium-based sunscreens when ACTUALLY they should be using the term 'physical' or 'mineral' sunscreen. And organic? The truth is any sunscreen can claim to be organic because they all contain 'organic compounds', which pretty much translates to containing carbon (hint: all living things). Organic is a totally different terminology when it comes to chemistry than it is when we are referring to food and produce so it's a good thing to be aware of!
Often these are perceived to be a better choice because they are 'natural' ingredients found in our environment. The truth is, these products also have to go through a chemical process to be suitable for use in sunscreen.