This is the time of year that we all need to worry about sunburn. We need the sun to make sufficient vitamin D, but sometimes it’s a fine line between not enough and too much. So, how can you ensure sufficient sun to make enough vitamin D without burning? A parameter called the Minimal Erythema Dose (MED) is used to measure the protection of various agents against sunburn. This is the minimum amount of UV light that produces redness 24 hours after exposure. Any substance that increases the MED is considered to be photoprotective. Here are some suggestions, but remember these are not a license to engage in excessive sun exposure, which can cause skin cancer and aging of the skin.
1. Orally administered beta-carotene markedly increases the protective effect of topical sunscreen at doses of 5-180 mg daily. The higher doses were more protective and it should be started a month prior to sun exposure. It takes at least 3 weeks to achieve protective levels in the skin.
2. Vitamin A has the potential to prevent UV-induced free-radical damage. Exposure to UV radiation causes a decrease in retinol (vitamin A) concentration in skin. When give orally at 50,000 units daily starting 2 days prior to sun exposure for up to 14 days, the severity of sunburn was rated as ‘less than usual’ by 66% of subjects. Fifty two percent experienced complete freedom from sunburn. Those with blond hair benefited the most from the treatment and those with auburn hair benefited the least. This dose of vitamin A is not recommended during pregnancy, in patients with liver impairment, malnutrition or alcoholism.
3. Oral vitamin C and E increased the MED by 21% when taken at doses of 2 gm/1000 IU, respectively, daily for 8 days. Neither of these supplements alone had any effect on the MED.
In good (warm) health,