Warm in the Tropics
For most of us, some tropical warmth sounds pretty nice right now. But there’s a lot more than just warmth in that nurturing sunlight.
About 50 years ago scientists began to recognize an intriguing pattern. Consistently higher rates of chronic diseases such as multiple sclerosis (MS), hypertension, and several types of cancer were recorded among people who lived outside of the tropical and subtropical latitudes nearest the equator. From this observation, researchers eventually concluded that the higher intake of vitamin D through sunlight provided protection against some diseases.
But even though this hypothesis about the protective effects of vitamin D have been known for some time, no prospective studies have tested vitamin D as a preventive agent against MS. Until now, that is.
Nurses on call
In this month’s issue of the journal Neurology, researchers at the Harvard School of Public Health reported on a study that used records from two phases of the Nurses’ Health Study. The diets and multivitamin use for nearly 190,000 women were followed for a period of 20 years during phase one (accounting for approximately half of the women), and 10 years in phase two.
A total of 173 cases of MS were reported. An analysis of the complete data showed two significant results:
- Women who had the highest intake of supplementary vitamin D, had a 40 percent reduced risk of developing MS compared with women who used no supplements at all.
- Risk of developing MS was not reduced for women who had vitamin D intake from food sources, but took no supplements.
This is the first study of its kind to assess MS risk with vitamin D intake, so further research will be necessary to confirm the conclusion that supplements may significantly reduce risk. Also, because of the nature of the available data, this study was unable to determine the effects that sunlight exposure might have on MS risk.
Nevertheless, the lead author of the study, Dr. Kassandra Munger, told BBC News, “It’s exciting to think something as simple as taking a multivitamin could reduce your risk of developing MS.” The women who benefited from supplement use all had a minimum intake of 400 IU of vitamin D each day.
Treatment follows
In addition to prevention, vitamin D may also be an essential element in the treatment of MS after the disease has been diagnosed.
In a small study in the mid-80s, researchers followed 10 MS patients for two years while they took daily supplements of vitamin D (5,000 IU), calcium (1,000 mg), and magnesium (600 mg). During the testing period, the subjects kept detailed records of their disease activity. When these records were compared to each of their personal histories, noting frequency of aggravation from MS symptoms, results showed a clear decline in the rate of disease activity after supplementation began.
Obviously, further studies are needed here also, but this study confirmed earlier trials that showed similar results using laboratory animals.
Blocked sun
Multiple sclerosis is an auto-immune disease, and additional studies have shown that people who live in areas furthest from the equator tend to be at higher risk from other auto-immune diseases as well.
In the November 2003 issue of Nutrition and Healing, Jonathan V. Wright, M.D., discussed the importance of supplementing with vitamin D. Dr. Wright noted that during the late fall, winter, and early spring, UVB rays from sunlight don’t penetrate earth’s atmosphere in non-tropical latitudes. So even if you’re an avid skier and spend a good amount of each week on the slopes, you still won’t get much, if any, vitamin D from sunlight. The “cut off” latitude is approximately 35 degrees. If you draw a line from Los Angeles to Charlotte, NC, just about everyone north of that line can be considered vitamin D deficient during the cold months of the year.
For those who can’t get enough sun, Dr. Wright recommends supplementing with 2,000-3,000 IU of vitamin D every day. He also suggests that those over the age of 35 should consider taking as much as 4,000 IU daily to help prevent osteopenia, a decrease in bone density that’s a precursor of osteoporosis.
If these levels sound high, they are by previous standards. But within the past few years, research has shown that the safe daily upper limit of vitamin D is 10,000 IU. In short: It’s hard to get too much of this good thing.
To Your Good Health,
Jenny Thompson
Health Sciences Institute
Sources:
“Vitamin D Intake and Incidence of Multiple Sclerosis” Neurology, Vol. 62, No. 1, 1/13/04, ncbi.nlm.nih.gov
“Vitamin D Almost Halves Women’s Risk of MS” NutraIngredients.com, 1/13/04, nutraingredients.com
“Vitamin D Pills Cut MS Risk” BBC News, 1/13/04, bbc.co.uk
“Vitamin D Supplementation in the Fight Against Multiple Sclerosis” Ashton F. Embry, DIRECT-MS, direct-ms.org
“Multiple Sclerosis: Decreased Relapse Rate Through Dietary Supplementation With Calcium, Magnesium and Vitamin D” Medical Hypotheses, Vol. 21, No. 2, October 1986, ncbi.nlm.nih.gov “The Essential Nutrient You Need More Of – And How To Get It Absolutely Free” Jonathan V. Wright, M.D., Nutrition and Healing, 11/1/03, wrightnewsletter.com