Decade ago, oncologists and dermatologists advised us to avoid exposure to the sun because of the risk of skin cancer. But like most things, we may have gone a little overboard in our compliance, and that has been to our detriment. In recent years, numerous studies have shown that having adequate amounts of Vitamin D in our bodies prevents many cancers, heart disease, metabolic syndrome and diabetes. In fact, the latest research seems to connect low levels of Vitamin D with a higher risk of developing Multiple Sclerosis.

Vitamin D aids in bone and tooth formation and also helps maintain heart action and proper functioning of the nervous system. It is present in sunlight, fortified milk and orange juice, fish, eggs and butter. The single best way to get a proper dose of D is to absorb some good old sunshine, as it is produced when ultraviolet rays hit the skin. It is often difficult to get sufficient amounts from food alone, and supplements are available to help you meet this goal. However, it is important to understand that supplements must be taken in exactly the proper dose for your size, age and skin type, and that taking too much D can cause a dangerous build-up of calcium in the body. But how much is enough and how much is too much?

It is estimated that over 50% of both the adult and child populations are deficient in Vitamin D. The recommended daily dosage of Vitamin D currently stands at 200-600 IU (International Units) per day. However, the Canadian Cancer Society says we should be getting at least 1,000 IU per day. Many researchers, including Dr. Bruce Hollis, Professor of Pediatrics, Biochemistry and Molecular Biology at the Medical University of South Carolina recommends 2,000 IU per day. But too much Vitamin D in the form of a supplement isn’t good either, as it can lead to a build-up of calcium, which causes blood toxicity – a serious problem. Dizziness, vomiting, incredible pain in your head and/or pain in your bones are all indications that you have too much Vitamin D in your system, and that the amount you are taking needs to be adjusted and in some instances, eliminated completely.

Contrary to years of warnings to stay out of the sun, more recent research indicates that getting a little too much sunshine is better than not getting enough and that in fact, one’s risk of cancer increases from not getting enough sunshine. We now know that getting as little as 15 minutes of natural sunlight 3 or 4 times a week – WITHOUT SUNSCREEN – can play a major role in helping to prevent cancer and other diseases.

A paper regarding the many factors influencing Vitamin D levels appeared in 2011 in Acta Dermato-Venerologica, a Swedish medical journal. Here are nine interesting factors as identified in the paper:

1. The latitude where you live. At higher latitudes, the amount of vitamin D-producing UVB light reaching the earth’s surface decreases in the winter because of the low angle of the sun. In Boston, for example, little if any of the vitamin is produced in people’s skin tissue from November through February. Short days and clothing that covers legs and arms also limit UVB exposure.

2. The air pollution where you live. Carbon particulates in the air from the burning of fossil fuels, wood, and other materials scatter and absorb UVB rays. Ozone absorbs UVB radiation, so holes in the ozone layer could be a pollution problem that winds up enhancing vitamin D levels.

3. Your use of sunscreen — in theory. Sunscreen prevents sunburn by blocking UVB light, so theoretically, sunscreen use lowers vitamin D levels. But as a practical matter, very few people put on enough sunscreen to block all UVB light, or they use sunscreen irregularly, so sunscreen’s effects on our vitamin D levels might not be that important. An Australian study that’s often cited showed no difference in Vitamin D between adults randomly assigned to use sunscreen one summer and those assigned a placebo cream.

4. The color of your skin. Melanin is the substance in skin that makes it dark. It “competes” for UVB with the substance in the skin that kick-starts the body’s vitamin D production. As a result, dark-skinned people tend to require more UVB exposure than light-skinned people to generate the same amount of vitamin D.

5. The temperature of your skin. Warm skin is a more efficient producer of vitamin D than cool skin. So, on a sunny, hot summer day, you’ll make more vitamin D than on a cool one.

6. Your weight. Fat tissue sops up vitamin D, so it’s been proposed that it might be a vitamin D rainy-day fund: a source of the vitamin when intake is low or production is reduced. But studies have also shown that being obese is correlated with low Vitamin D levels and that being overweight may affect the bioavailability of Vitamin D.

7. Your age. Compared with younger people, older people have lower levels of the substance in the skin that UVB light converts into the Vitamin D precursor, and experimental evidence indicates that older people are less efficient Vitamin D producers than younger people. Yet, the National Center for Health Statistics’ data on Vitamin D levels fly in the face of the conventional wisdom that Vitamin D inadequacy is a big problem among older people. They don’t show a major drop-off in levels between middle-aged people and older folks.

8. The health of your gut. The Vitamin D that is consumed in food or as a supplement is absorbed in the part of the small intestine immediately downstream from the stomach. Stomach juices, pancreatic secretions, bile from the liver, the integrity of the wall of the intestine — these all influence the amount of the vitamin is absorbed. Therefore, conditions that affect the gut and digestion, like Celiac Disease, Chronic Pancreatitis, Crohn’s Disease and Cystic Fibrosis, can reduce Vitamin D absorption.

9. The health of your liver and kidneys. Some types of liver disease can reduce absorption of Vitamin D, as the ailing liver isn’t producing normal amounts of bile. With other types, steps essential to Vitamin D metabolism can’t occur — or occur incompletely. Levels of the bioactive form of Vitamin D tend to track with the health of the kidneys, so in someone with kidney disease, bioactive Vitamin D levels decrease as the disease gets worse, and in end-stage kidney disease, the level is undetectable.

Research in the area of Vitamin D is ongoing, and Vitamin D continues to look very, very promising as a tool in the prevention of numerous ailments and diseases. In addition to heart disease, many cancers and immune system diseases like MS, it seems to help prevent rheumatoid arthritis, infectious diseases such as the flu and perhaps mental illnesses such as Schizophrenia and Depression. So it seems that a little sunshine can go a long, long way, and indeed can “add hours to your day, days to your year and years to your life.”

Alan Freishtat is an A.C.E. CERTIFIED PERSONAL TRAINER and a LIFESTYLE FITNESS COACH with over 16 years of professional experience. He is the co-director of the Jerusalem-based weight loss and stress reduction center Lose It! along with Linda Holtz M.Sc. and is available for private consultations, assessments and personalized workout programs. Alan also lectures and gives seminars and workshops. He can be reached at 02-651-8502 or 050-555-7175, or by email at [email protected], www.loseit.co.il USA Line 1-516-568-5027.

(Alan Freishtat – YWN)