By
Roy M. Arnold, MD
A study published in the journal “Nutritional Research†in 2011 found a substantial prevalence of Vitamin D deficiency among a large sample of US adults. Forty-two percent of those tested had a level less than 20 nanograms per milliliter (ng/mL.) A significant additional number had insufficient levels between 20 and 29. Those most likely to be deficient were older, had darker skin, were overweight, consumed lower amounts of dairy and spent a great deal of time indoors.
Since opening my practice in April, I have identified about one new case of Vitamin D deficiency per month. This incidence is high enough that I now routinely screen for it in older adults and in women of child-bearing age. Many people who are identified with low levels had no symptoms, while others complained only of vague symptoms such as low energy, generalized aches and pain or poor motivation.
Vitamin D has often been called “the sunshine Vitamin†because our skin can manufacture it when we spend time outdoors in the sun. With our concerns over skin cancer from sun exposure and with our modern indoor lifestyle, many people simply don’t manufacture enough to maintain a healthy level. The food you eat is the best source for most vitamins and minerals that your body needs, but there isn’t enough Vitamin D in food to meet your body’s requirements. There are only 2 ways to meet Vitamin D requirements: Expose your bare skin to direct sunlight, or take supplements.
What does Vitamin D do in the body? First and foremost Vitamin D is vital for strong bones. Calcium and phosphorus are used by the body to build strong bones. Without enough Vitamin D, these minerals cannot be absorbed into the body. Deficiency in children causes a condition called Rickets where the long bones are very soft and become deformed causing bowing. In adults, deficiency can contribute to softening of the bones and make us prone to fractures of the hip, wrist and spine.
Beyond its vital effect on the bones, Vitamin D is also essential for immune function, muscle function, cardiovascular and respiratory health, brain development and can fight certain types of cancer. Researchers are constantly discovering new information about how Vitamin D affects our bodies. Thus far there is evidence that a lack of vitamin D has been associated with certain types of cancer, asthma, type-II diabetes, high blood pressure, depression, Alzheimer’s and autoimmune diseases like multiple sclerosis, Crohn’s and type-I diabetes.
Let’s look at some of the evidence: The strongest evidence for Vitamin D deficiency being associated with cancer is in colorectal cancer. There is an inverse relationship between serum levels of Vitamin D and the likelihood or colorectal cancer development, that is to say the lower the level, the more likely the patient will develop colorectal cancer. There is a growing body of evidence of an association between breast cancer and low Vitamin D levels. There is also some evidence that cancer patients often
have low levels but the evidence is not yet developed that shows raising the level decreases the rate of growth of the cancer.
In several studies, low Vitamin D levels were associated with high blood pressure and indirectly with its end organ damage – strokes and heart attacks.
Vitamin D deficiency can contribute to insulin resistance and therefore indirectly to obesity and Type II diabetes.
Immune-related diseases like multiple sclerosis, Crohn’s disease, lupus, rheumatoid arthritis and Type I diabetes may be associated with Vitamin D deficiency because the vitamin has been found to bind to the specific gene sites associated with these disorders. More research is necessary before any conclusions can be drawn about the effects of Vitamin D on the diseases themselves.
A large meta-analysis published last year in the journal Neurology concluded that lower Vitamin D levels were linked to lower cognition and dementia in elderly adults. One early study even reported a regression of the Alzheimer’s plaques when the vitamin levels were corrected. Clearly, more research is needed in this area. Stay tuned.
Supplementation – If you decide to take a vitamin D supplement, most experts recommend taking 2,000-5,000 International Units daily. Make certain that the supplement is labeled “Vitamin D3.†It is not wise to exceed 5,000 units per day since excess levels of Vitamin D can cause problems with kidney stones, kidney failure, gastrointestinal problems, poor balance, or confusion. Persons identified with Vitamin D deficiency often need medical supervision and monitoring of the Vitamin D levels to ensure they are completely corrected. If you have concerns about your Vitamin D levels by all means discuss them with your primary health provider.
