Vitamin D deficiency is likely contributing to an increase in late winter and early spring colds and flu, according to several new and impressive studies done in the last few years. As the temperatures fluctuate between the seasons, there is added stress to our bodies and immune systems. Combine that with low levels of vitamin D because of reduced exposure to the sun during the winter months, and the spike in colds and flu can be anticipated.
According to researcher and author Dr. David Williams, studies over the last several years have also linked low levels of vitamin D with 18 different kinds of cancer, including breast, prostate, colon, and ovarian. He claims that vitamin D deficiency has gone unnoticed for many years by most researchers and those in the medical field. As a result, we are now seeing the effects of vitamin D deficiency, especially in the elderly.
According to the Vitamin D Council, vitamin D deficiency also contributes to heart disease, stroke, hypertension, auto-immune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects and periodontal disease.
Vitamin D is a natural antibiotic and antiviral compound, and researchers have found that a person’s vitamin D level has a direct influence on whether they succumb to the flu, a cold, or some other form of infection. Some researchers have gone so far as to say that vitamin D deficiencies are absolutely the reason influenza epidemics are seasonal, making us more susceptible to respiratory infections during the winter to spring months. As a result of these repeated findings, many medical doctors are now suggesting their patients pay more attention to a diet rich in vitamin D, vitamin D supplements, and more exposure to the sun.
Dr. John Cannell of the Vitamin D Council recently published a study that supports researchers’ claims that vitamin D levels, exposure to the sun, and flu and colds are inter-related. Some of Dr. Cannell’s observations were:
Flu season occurs in the months following the shortest day of the year, when vitamin D levels are at their lowest; flu disappears after the longest day of the year.
Flu is more common in the tropics during the rainy season.
Children exposed to sunlight are less likely to get colds.
Cod liver oil, one of the richest food sources of vitamin D, reduces viral respiratory infections.
UVB sun lamps, which produce vitamin D in the skin, reduce colds and flu in school children and factory workers.
Children who suffered from frequent colds and flu suddenly became infection-free when given high doses of vitamin D.
In 1980, University of California epidemiologist Cedric Garland published a study showing that rates of colon cancer were about twice as high in the northeastern United States, where there is less sun, than in the south where it’s much more sunny.
Does this mean vitamin D will cure cancer? A Harvard study found that the mortality rates were 40% higher among lung cancer sufferers who underwent surgery in the winter than among those who had a summer surgery and had increased levels of vitamin D from either the sun or their diet. This is not to say, however that a high vitamin D level will prevent cancer in a chronic smoker, for example.
How much vitamin D do we need each day? According to Dr. Williams, it’s been estimated that our body needs 4,000 IU of vitamin D per day, every day, from all sources (sun, food, supplements). He reports that toxicity isn’t likely to begin before an extended period of 10,000 IU a day, and some researchers believe that number may actually be closer to 40,000 IU a day. The bigger problem is not correcting the deficiencies that many already have.
According to Dr. Williams, “one 20-minute full-body exposure to the summer sun will result in putting 20,000I IU into the body within 48 hours,” unless you’re dark-skinned, elderly, obese, a vegetarian, using sunscreen, or taking cholesterol-lowering drugs. In those cases, the IUs will be considerably less. Since such daily sun exposure isn’t realistic for most people, eating high quality fish (salmon, mackerel, tuna, sardines), drinking milk, and taking cod liver oil and a good quality vitamin D supplement will go a long ways in improving our resistance to colds, flu, and serious diseases.