Monthly Archives: April 2008

Understanding Vitamin D…

written by Katolen Yardley, MNIMH, Medical Herbalist

During the winter months of limited sunlight exposure or in the case of individuals who rarely are exposed to sunlight, vitamin D deficiencies may be prevalent.

Known as the sunshine vitamin and manufactured on the skin, Vitamin D is converted by the liver to an inactive storage form called calcidiol (25-hyrdoxy vitamin D) and then converted again by the kidneys into the biologically active form 1,25-dihydroxy Vitamin D (also known as 1,25 dihydroxycholecalciferal), which is stored in fat calls and also circulates through the bloodstream.

Vitamin D is involved in the production of numerous proteins and enzymes used to fight disease, repair muscles, strengthen bones and maintain overall health. Vitamin D works with Magnesium to stimulate the absorption of Calcium into the bones and works best taken together with these minerals.

When outdoors and before application of a sunscreen, exposure of the arms, legs and face to the suns ultraviolet rays for 15 minutes daily will likely ensure adequate levels of Vitamin D synthesis into the body.

Studies indicate that deficiencies of Vitamin D can be a contributing factor in the development of colon cancer, breast cancer, prostate cancer, diabetes, metabolic syndrome, high blood pressure, osteoporosis, infectious disease, and inflammatory bowel disease and auto immune dysfunction such as: rheumatoid arthritis, lupus and multiple sclerosis. Research is also indicating that daily Vitamin D supplementation offers protection against the development of rickets, osteoporosis, colorectal, prostate and breast cancer. Supplementation with Vitamin D cannot guarantee the development of these disorders; however it is certainly one of many nutrients known to protect the body from onset of chronic disorders.

Food sources of Vitamin D include salt water fish, egg yolks, dandelion greens, sweet potatoes, tuna, vegetable oils, salmon, halibut, sardines, herring, mackerel, parsley, nettle, horsetail and alfalfa.

Individuals suffering from malabsorption problems such as celiac disease or crohn’s may not be absorbing adequate amounts of Vitamin D; certain medications such as some cholesterol medications, antacids, mineral oil, steroids, cortisone and thiazide diuretics can also interfere with absorption of Vitamin D.

In supplement form, there are 2 types of Vitamin D: Naturally occurring and the most active form, D3 or cholecalciferol (from fish oil, eggs, organ meats, sheep’s wool, cod liver oil and plant sources)and the synthetic, irradiated D2 or ergocalciferol, (less biologically active) and found in fortified foods, fortified milkand some supplements.

Ensure you take only the naturally occurring pure Vitamin D3 (cholecalciferol), as the body assimilates this in the same way that it uses Vitamin D formed from sunlight. Avoid ingestion of the synthetic Vitamin D2, as similar to many synthetic products, the synthetic Vitamin D has been shown to be toxic in high dosages.

Determine your need for supplementation with Vitamin D before you take it. A lack of vitamin D will contribute to many chronic illnesses however like many fat soluble vitamins, Vitamin D is stored in the body thus taking too much is not desirable; request a calcidiol 25-hydroxyvitamin D (or a 25(OH)D) blood test from your doctor to determine if you are deficient. Ideal calcidiol [25-hydroxy vitamin D] levels are between 35-65 ng/ml [87-162 nm/L], year around.

Individuals with sarcoidosis, tuberculosis, or lymphoma should avoid the use of Vitamin D supplementation without first consulting a health care professional.

For more reading please click on the following Vitamin D links:

The Cholecalciferol Council