#sunblock protects the #skin from harmful cancer-causing rays, but this #protection means you're also #absorbing less of what the body needs to make #vitaminD. Anything over SPF 8 cuts #ultravioletproduction by more than 75 percent. 10 to 20 minutes per day of unprotected #sunexposure is generally enough for lighter skinned people, while those with darker skin need about an hour of unprotected #sunlight. After this time has elapsed, it is best to apply sunscreen to get those #protectivebenefits.