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Vitamin D and Sunscreen

The Controversy about Sunscreen vs Vitamin D from Tanning

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Updated September 03, 2008

The controversy about vitamin D and sunscreen has been a source of argument for many years. The basic question is, "Which is more important?"
Wearing sunscreen and limiting sun exposure to prevent skin cancer
or
Getting the beneficial effects of vitamin D by tanning

Why is Vitamin D Important?

Vitamin D's main purpose is to keep normal levels of calcium and phosphorus in the bloodstream. Calcium needs vitamin D to help transport it from digested food in the stomach and small intestines to the bloodstream. In the body calcium keeps bones strong. There is also some research that suggests that vitamin D may help prevent osteoporosis, high blood pressure, cancer, and some immune-system diseases. There are two forms of vitamin D that are important in humans:
  • Vitamin D2: Ergocalciferol, which comes from plants
  • Vitamin D3: Cholecalciferol, which comes from exposure to UV radiation and certain foods

"The Vitamin D from Tanning" Argument

There are people who say it's OK to tan in tanning beds or even be out in the sun without wearing sunscreen because that UV exposure produces vitamin D with all of its beneficial effects.

The Problem With the "Vitamin D from Tanning" Argument

There are many reasons why this argument is incorrect.
  • Skin Cancer is Bad: The number of new skin cancer diagnoses is rising so rapidly it's considered an epidemic. More than 1 million people will be diagnosed with a new skin cancer this year. Out of all the skin cancers, melanoma is the most dangerous, and one person dies from melanoma almost every hour in the United States.
  • UV Radiation Causes Skin Cancer: Good scientific studies show that exposure to UV radiation causes skin cancer. In addition, that exposure also causes photoaging. Not only can exposure to UV radiation kill you, it can make you look bad too.
  • Dietary Vitamin D Works: Once vitamin D is in the body it has to be processed by the liver and the kidneys into a usable form. Whether the source is dietary or sun exposure, once vitamin D is processed, the effect is the same. In other words, your body doesn't know whether the vitamin D it's using came from the sun or your diet.
  • Vitamin D May Not Prevent Cancer: While there are some studies that suggest vitamin D may help prevent certain cancers, well-designed scientific studies have not confirmed this.

Sources of Dietary Vitamin D

You can get vitamin D from a variety of sources. Foods such as salmon, sardines, shiitake mushrooms, and egg yolks naturally contain vitamin D. Some foods like milk, orange juice, yogurts, and cheeses can be fortified to increase their vitamin D content. Finally, there are prescription and over-the-counter vitamin D supplements that come in capsules and liquids.

How Much Vitamin D Do You Need?

The FDA's recommended daily allowance (RDA) of vitamin D is:
  • 200 IU per day for children and adults <50 years old
  • 400 IU per day for adults >50 years old
  • 600 - 800 IU per day for the elderly >70 years old

How Much Vitamin D Do You Really Need?

Most scientists and nutritionists believe that the doses in the RDA are not high enough. Furthermore, good studies show that up to 10 times the recommended daily allowance is safe. Most experts agree that children and adults who stay out of the sun require 800 to 1000 IU daily.

Get more in-depth information about sources of vitamin D.

Sources:

American Academy of Dermatology. "Vitamin D Fact Sheet." Accessed 4 August 2008.

Gilchrest, BA. "The A-B-C-Ds of Sensible Sun Protection." Skin Therapy Letter. 13(2008): 1-5.

Gilchrest, BA. "Sun protection and Vitamin D: three dimensions of obfuscation." Journal of Steroid Biochemistry and Molecular Biology. 103(2007): 655-63.

Holick, MF. "Vitamin D deficiency." New England Journal of Medicine. 357(2007): 266-81.

Wolpowitz, D, and BA Gilchrest. "The vitamin D questions: how much do you need and how should you get it?" Journal of the American Academy of Dermatology. 54(2006): 301-17.

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