Vitamin D and Ultraviolet Radiation from the Sun or Artificial Tanning Lights.

What is Vitamin D

Most people have heard that vitamin D is essential for healthy bones.  That is the simple part of what is known about this vitamin, which is actually a hormone.  Vitamin D may prevent fractures and falls in the elderly; skin, colorectal, prostate, and breast cancer; cardiovascular and autoimmune diseases; and maintains healthy bones.  For years vitamin D sat quietly in the background while other vitamins, like E or C took the media spotlight. In the last decade or so, research has provided significant insight into the importance of this vitamin. 

Importance of Vitamin D

This past March in Toronto, Ontario, a group of experts hosted a Vitamin D, Ultraviolet Radiation, and Health conference.  At the conference there was a lot of discussion about the low vitamin D levels seen in Canadians.  Marie Traynor from the Ontario Public Health Association stated “there is an insufficient vitamin D epidemic occurring in Canadians, likely due to our northern latitude”.  Experts at the conference announced the formation of Canada’s first Vitamin D Foundation.  The foundation is committed to answer the question how much vitamin D is enough and how Canadians can get enough vitamin D from the sun or their diet.

Vitamin D and Diet

There are actually very few foods naturally rich in vitamin D.  Sources of foods that provide vitamin D include fish liver oils, fatty fish/cold saltwater fish (e.g. halibut, herring, oysters, salmon, shrimp, tuna), and eggs from hens fed vitamin D.  To help Canadians get vitamin D from their diet, the Canadian food industry is required to fortify milk and margarine.  Dietary sources of vitamin D include cow’s milk, fortified plant-based beverages, such as soy or rice milk, and margarine.  Foods like cheese, butter, yogurt or cottage cheese are commonly thought by the public to contain vitamin D.   Use the nutrition information on food labels to determine if a product contains vitamin D.  You might be surprised to learn that your favourite yogurt or cheese does not provide any vitamin D. 

Vitamin D and Supplements

Store shelves offer many dietary supplements containing vitamin D, but the question is “how much is enough or too much?”   You might also think taking a vitamin each day will help keep your vitamin D at a healthy level.  Unfortunately, it is not that simple.  Experts are considering revising vitamin D recommendations in view of increasing evidence indicating current levels are too low.  This is especially important for the frail elderly and possibly people with dark skin.  Talk to a health care professional about your need for vitamin D or other supplements- especially if you avoid the sun.

Vitamin D and Ultraviolet Radiation

People can also obtain vitamin D through exposure of their skin to natural sunlight or artificial tanning lights.  However, over-exposing skin to ultraviolet radiation from the sun or tanning lights will very likely result in health problems. Ultraviolet radiation increases your risk of developing skin cancer, and cataracts, and may change the way your immune system protects the body from diseases.

Some tanning bed owners promote the use of artificial tanning, which exposes skin to harmful Ultraviolet radiation as one way to get vitamin D.   The tanning bed industry is not regulated to make medical claims.  Fabutan, a leading indoor tanning corporation, recently settled a dispute with the Competition Bureau of Canada about promoting indoor tanning as a healthy way to get vitamin D.  Fabutan agreed to stop promoting unproven health benefits related to indoor tanning (Competition Bureau, March 3, 2006).  They agreed to a $62,500 monetary penalty while the president of the corporation agreed to donate $12,500 to a charity.  Health Canada advises all Canadians to become informed before deciding to expose themselves to Ultraviolet Radiation from artificial tanning lamps.

How Much Exposure to the Sun do we Need?

Knowing how much time to spend in the sun to get enough vitamin D is tricky.  Things like age, skin colour, what part of the country you live in, your body’s sensitivity to the sun, cloud cover, time of the year, time of day, amount of clothing covering the skin, and other factors play a role in how much vitamin D your body is able to manufacture in a certain period of time outdoors.

The sun emits 3 types of ultraviolet radiation, ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC).  Only UVA and UVB reach the earth’s surface.  Vitamin D is made in the body when UVB penetrates the surface of the skin.  The production of vitamin D is blocked when sunscreen is used.

In 2005 researchers collected information about tanning, sunscreen, skin cancer and vitamin D.  The Canadian study assessed the perception of how much time should be spent in the sun to get enough vitamin D.  Subjects identified a range of time from as much as ‘more than one hour’ to as little as ‘less than 5 minutes’ needed to get enough vitamin D.  Almost half of Canadians asked did not know how much time in the sun is required to get enough vitamin D. 

The Canadian Dermatology Association recommends “only brief sun exposure to either the back of the hands, arms, or face, two to three times a week from May to September is required to maintain sufficient vitamin D levels.”  Any longer than a brief exposure and the process of making vitamin D is inactivated.  For some people a few minutes of exposure to the sun can maintain healthy levels of vitamin D, but for others the same amount of exposure to the sun may put their health at risk. 

This year leading national health organizations in cancer, dermatology, public health, bone and immune system health plan to provide Canadians with up-to-date health messages about skin cancer prevention, sun exposure, and health.  Although new messaging is expected, there is one message that is very strongly supported by research; that is the need to continue to reduce the risk for skin cancer by protecting skin from over-exposure to ultraviolet rays from the sun and tanning salon lights.

Watch for more information on this important health issue in the near future.  In the mean time:

• Reduce exposure to the sun between 10 a.m. and 4 p.m.
• Seek shade or create your own
• Wear a wide brimmed hat
• Wear sun protective clothing
• Use sunscreen, SPF 15+
• Wear ultraviolet protective sunglasses
• Eat vitamin D rich foods, like fortified milk and fortified milk products
• Talk to a health care professional if you are considering a vitamin D supplement

Craig Sinclair, a skin cancer specialist from the World Health Organization maintains the current Canadian diet will not provide an adequate source of vitamin D.  Canadians need a balance between exposure to natural sunlight and dietary sources of vitamin D.

Recommended Sources of Vitamin D:

• Sun
• Supplements
• Food

Reliable links:

Health Canada - It's Your Health:  Tanning Lamps

Canadian Cancer Society- Vitamin D Conference, March 2006

Health Canada - Guidelines for Tanning Salon Owners and Operators