Time to test your levels & raise your wellness
In the early 20th century, children in Europe and northern United States developed Rickets due to lack of sun exposure. This led to initial research into the importance of Vitamin D in the human body. Rickets (in children) and osteomalacia (in adults) occur due to poor mineralization of the collagen matrix associated with bones. The human body creates Vitamin D (from 7 dehydrocholesterol) in the skin with exposure to UVB (290-315nm) from the sun. Many Vitamin D experts advise 10-15 minutes of exposure over 40% of the skin (using facial sunscreen) daily or 20-25 minutes three times weekly to meet the body’s requirements. However, there are many obstacles to this simple option of outdoor communing with nature. Geography is the first, as latitudes above 35 degrees North (ie Atlanta) receive less UVB in winter. Fear of skin cancer, resulting in less outdoor activity and increased use of sunscreens is another obstacle to nature meeting our body’s requirement. Cedric Garland, PhD from University of California, San Diego Medical School states “responsible, routine sun exposure will save 10 lives from non-skin cancers for every 1 skin cancer death.” An SPF of 8 is sufficient to block the synthesis of vitamin D from exposure to sunlight. Age and ethnicity also contribute to the obstacles in a natural supply of vitamin D. Darker pigmented persons require more sun exposure for solar synthesis and elderly persons may have impaired skin synthesis (of up to 75%) due to age. Since vitamin D created from solar exposure is converted to its active form by the liver and kidneys, persons with organ damage also have limited capacity. Thus, in the 1940s, the supplementation of vitamin D in industrialized countries began and Rickets became rare.
However, the problem of deficiency of vitamin D was far from resolved. Studies have found that up to 93% of patients admitted to the Emergency Room for bone pain and muscle aches were found to be deficient in Vitamin D. In postmenapausal women on prescription medication for the treatment of Osteoporosis over 50% were deficient. Amongst youth, over 50% of Black & Latino teens and almost 50% of White preteens were found to be deficient in studies. Even amongst pregnant and lactating women taking a prenatal vitamin with 400IU of vitamin D, 73% were found to be deficient (90% ate fish; 93% had 2-3 glasses of milk daily in addition to the vitamin). So, if Rickets is rare, why does deficiency matter?
The 21st century has brought forward many exciting results of research on Vitamin D. Postmenapausal women who increased their vitamin D intake by 1100IU reduced their cancer risk by 60 – 77%. We know that living in more northerly latitudes of the U.S. is associated with increased incidence of ovarian, colorectal, and renal cancers. And, that incidence of Crohn’s, Type I Diabetes, and Multiple Sclerosis is higher at higher latitudes. Now, Swedish studies have shown that patients with Type I Diabetes had lower vitamin D levels than those not affected. A study of military personnel showed that with regard to Multiple Sclerosis, the incidence was 62% lower in persons with the highest vitamin D levels when compared to persons with the lowest levels. In a review of 63 scientific papers, the rates of Breast, Ovarian, Colorectal and Prostate cancers were decreased by fifty percent with vitamin D supplementation (1000IU for men & 1500-2000IU for women). Thus, the significance of vitamin D is far greater than its contribution to bone metabolism and the maintenance of bone health.
Vitamin D regulates calcium and phosphorus absorption by the intestines, and deficiency can result in only 10-15% calcium & 60% phosphorus absorption. Vitamin D also affects the healthy development of red blood cells, regulates cell growth, secretion of insulin and parathyroid hormone, and is a modulator of the immune system. So, it has an important role in anti inflammatory, neuroprotective, and cellular regulatory functions. Psorias and wound healing are improved with vitamin D via skin production, topical or supplemental forms. New research has shown that vitamin D reduces the rate of physical decline in seniors. Increasing levels resulted in improved performance speed and proximal muscle strength.
Deficiency (<20ng/ml) in utero can cause growth abnormalities and childhood skeletal deformities. Studies have shown that increased vitamin D levels in pregnancy reduced the development of offspring’s autoantibodies to cells of pancreas. Deficient levels are associated with a 30-50% increase in the risk of Colon, Prostate, and Breast cancers. Deficiency is also associated with Depression and Schizophrenia. Published studies of elderly women show that those with the lowest vitamin D levels are the first to fall; and, supplementation reduces fall risk. Osteoporosis affects one third of women in their sixties and two thirds of women over eighty. The risk of developing this disease is reduced by calcium and vitamin D supplementation. Studies have also shown that taking vitamin D reduced the risk of Multiple Sclerosis, Rheumatoid Arthritis and Osteoarthritis.
Vitamin D is now well understood to be one of the body’s best defenses against certain cancers, psychiatric conditions, skin & respiratory infections, autoimmune diseases; as well as being a major regulator of bone health and maintenance of physical performance. Normal levels in blood tests (25 hydroxyvitamin D) should be at least 40ng/ml. Dietary sources include salmon, mackerel, sardines, tuna, and cod liver oil (also contains vitamin A which some experts say can inhibit uptake of vitamin D). Dairy is not an adequate dietary source. Supplements are generally with calcium over the counter. The calcium citrate maleate is less likely to cause kidney stones than calcium carbonate. At least 800IU daily should be supplied by supplement. Persons found to be deficient are given 50,000IU/week for six to eight weeks, then levels are rechecked. Persons found to be insufficient are given 1000-2000IU/daily. The cost of supplementation has been estimated at 5 cents/person. This pales by comparison to the health care costs from the medical consequences of widespread deficiency. So, “move over turkey”, this Thanksgiving you may want to consider adding an oily fish to the meal of gratitude. Or, alternately, you can plan a quick Black Friday excursion closer to the equator.