The TRUTH about sunscreen protection
First, it's probably key to understand that UV radiation reaches the earth in the form of UVB and UVA rays.
UVB radiation plays a key role in skin cancer.
UVA radiation plays a key role in skin ageing, and suggested to aid to initiate some skin cancers.
1) SPF is related to UVB protection only.
2) SPF 15 sunscreen blocks 93% of UVB radiation,
SPF 30 sunscreen blocks nearly 97% of UVB radiation,
SPF 50 sunscreen blocks 98% of UVB radiation. (Minimal improvement)
3) In everyday life, most people UNDER apply their sunscreen achieving approximately 1/3 of the labeled indicated SPF value. Furthermore- people don't re-apply regularly, so that 1/3 of a dose doesn't even last long.
2) There is no measurement for UVA. Actually, not all sunscreens have UVA protection. If they do, consumers can't know exactly how much UVA protection they have. Individuals applying high-SPF sunscreens may not burn (UVB is the chief cause of sunburn), but without UVA-screening ingredients they can still receive large amounts of skin-damaging radiation.
3) If you want to protect your ageing risk as well as your skin cancer risk- look for UVA-blocking ingredients: zinc oxide, titanium dioxide, avobenzone, ecamsule, and oxybenzone. These sunscreens may be labelled "multi spectrum, broad spectrum, or UVA/UVB protection."
4) Visible light/ near infrared radiation (NIR) is also suggested to play a major part in the ageing process. Leading cosmeceutical brands have commenced to create UVA/UVB/NIR protective bases.
5) High SPFs can create a false sense of security, prompting consumers to stay out in the sun longer. Sun damage (for example, UVA damage) can take place without skin-reddening doses of UV radiation, and even the best sunscreens should be considered just one vital part of a comprehensive sun protection.
Buy at least SPF 30+ UVA/UVB Broad spectrum
Apply daily and regularly (even on cloudy days)
A cosmetically elegant sunscreen (fluid and non-sticky) can be used if you are intending to do everyday, mostly indoor things/ office/ in and out of the car.
If outdoors active (reapply 2hourly)- a thick sticky one that has a strong protective barrier like Zinc Oxide/ titanium dioxide- it will turn you a little white!
Don't forget to cover up with shade, hat, shirt etc.
If you are worried about getting enough Vitamin D- speak to your Dr and pop a Vitamin D tablet.