By Mel Huff Times Argus Staff



 

MONTPELIER – A lack of vitamin D, which is produced by skin when exposed to the sun’s rays, correlates with a wide variety of diseases including many cancers, according to Dr. John Matthew, the medical director of The Health Center in Plainfield.

While it’s not understood why more people with vitamin D deficiencies get these diseases than people with adequate levels, the correlation is so compelling that it makes sense to give the vitamin to everyone whose level is low, Matthew said. The Health Center screens all its patients for vitamin D deficiency.

Matthew, speaking to the Vermont Dietetic Association’s annual conference last week, noted the following relationships:

  • degenerative joint disease in knees progresses three times as fast when vitamin D levels are low;
  • ovarian cancer rates in Norway and Iceland are fives times greater than in equatorial regions;
  • multiple sclerosis rates rise the farther away from the equator people live;
  • Type I diabetes rates follow the same curve; (but Finnish infants who were given 2,000 units of vitamin D for a year had an 80 percent lower lifetime risk of developing Type I diabetes);
  • vitamin D deficiency is associated with higher rates of tuberculosis, influenza and other infections; and
  • low wintertime vitamin D levels correlate with increased coronary artery disease, asthma, greater insulin resistence, higher triglycerides and age-related macular degeneration.On the other hand, taking 800 units a day of vitamin D produces a 70 percent reduction in falls among people over 70 living in nursing homes. And increased exposure to UVB, the middle part of the ultraviolet spectrum that turns on the skin’s production of vitamin D, has been associated with reducing the rates of 18 different kinds of cancer. Matthew, who serves on the faculty of the University of Vermont College of Medicine and Dartmouth Medical School, presented the information to more than 100 people who attended the Vermont Dietetic Association’s annual conference on Thursday.

    The same day, the Association of Clinical Oncology released the conclusions of a Canadian study that found that breast cancer in women who had a vitamin D deficiency when they were diagnosed was 94 percent more likely to spread to other organs, compared to that of women with adequate levels of vitamin D, and the cancer was 73 percent more likely to be fatal.

    “These data indicate an association between vitamin D and breast cancer outcome, but we can’t say at this time if it’s causal,” Dr. Pamela Goodwin, the lead author of the breast cancer study, said at a press conference Thursday.

    Matthew, too, cautioned that “correlation does not equal causality.” He explained that low vitamin D levels are associated with depression, but said, “It could be that people who are depressed don’t go out in the sun.”

    “So why do people have deficiencies?” he asked.

    Human beings evolved in equatorial Africa, where their skin received a lot of sunlight, but they migrated into the higher latitudes where sunlight passes through the atmosphere at an angle, screening out much of the ultraviolet light.

    In Vermont, there is no UVB in the sunlight from November to March. “You could sunbathe all day from November to March. You’d be cold, but you’d make no D,” Matthew said. Consequently, vitamin D deficiency is prevalent.

    For most people, getting vitamin D from natural sources is impractical – even in warm weather they aren’t out in the sun for 15 minutes every day with 40 percent of their skin exposed, and they would have to drink 20 to 40 glasses of milk a day to get the amount they need.

    Despite the lack of randomized, double-blind trials like those used to test the safety and efficacy of drugs, Matthew sees using supplements to raise people’s vitamin D levels as an inexpensive and low-risk way of improving their health.

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