A Vitamin D deficiency is not an excuse to spend large amounts of time in the sun without the use of sunscreen.

Scientific studies by Switzerland’s of Pharmacology and Toxicology conducted in 2001 prove chemical sunscreens have detrimental consequences. Chemical compounds in sunscreens can accumulate in body fats and in mother’s breast milk. These chemicals mimic estrogen and can cause hormonal changes within the body such as increasing the size of the uterus...

Sun Protection Factor Ratings (SPF)

SPF is a measure of a sunscreen's effectiveness in providing protection against UVB rays.

How much UVB does SPF 15 actually block? How about SPF 30? Based on the Colipa (European) sunscreen regulations:
For SPF 15, 93% of the harmful UVB rays are blocked
For SPF 20, 95% of the harmful UVB rays are blocked
For SPF 30, 97% of the harmful UVB rays are blocke...

SPF, or Sun Protection Factor, increases the length of time you can stay outside in the sun without incurring sunburn or irritation from UV-B rays. At present there is no standard to measure protection from UV-A rays.

Calculate your recommended SPF:

• Rate yourself:
  Select your skin type. The corresponding amount of time indicates how long you can stay safely in the sun before burning.
  Fair skin - 10 m...