by Dr. Sara Kinnon
Over the past few years, Vitamin D has been receiving increased attention in research fields and subsequently in the media. Are you confused? Do you think Vitamin D might be for you?
Vitamin D is an essential fat- soluble vitamin that has many hormone activities in humans. In fact, most cells in our body have Vitamin D receptors. It has been suggested that vitamin d might be influential in over 2000 mechanisms in the body! So far, research suggests that Vitamin D has an effect on disease states and disorders such as multiple sclerosis, Diabetes (Type I&II), Hypertension (high blood pressure), Osteoporosis, and certain cancers. Its most known roles are to improve the absorption and utilization of calcium and phosphorus, stabilize the nervous system, and normalize heart functions.
Many people might assume that if they eat a balanced diet then they are maintaining adequate levels of Vitamin D. This is proving to not be the case. Firstly, Vitamin D dietary sources are limited, with the major sources being Cod Liver Oil, butter, eggs, halibut liver oil, herring, mackerel, meat, milk, salmon, and sardines. Secondly, recent studies, published in the Journal of Clinic Nutrition suggest that the amount of vitamin d eaten in our diet is at inadequate levels to avoid a deficiency. Couple this with limited sun exposure, and a Vitamin D deficiency is almost certain. Why is sun exposure necessary or helpful? When exposed to ultraviolet rays, our body can synthesize vitamin d. The amount of vitamin D manufactured due to sun exposure depends on a number of factors, like the amount of time spent in the sun and how much skin is exposed directly to the sun.
There are two forms of Vitamin D that are widely discussed in research and doctor’s offices. These are Vitamin D2 (1,25) and Vitamin D3 (25, OH). When determining one’s Vitamin D status, D3 or 25, OH Vitamin D is the most accurate. D3 is what is made in the skin, when sunlight converts the cholesterol derivative to d3. From here, it is converted to the active form, D2.
Who needs Vitamin D? Research suggests that the minimum level of 25, OH Vitamin D is 30 ng/ml in order to benefit. However, greater than 55 is of benefit in protecting against many conditions, such as breast, prostate, or colon cancer. With varying levels offering different benefits, the consensus is suggesting optimal levels are actually between 40 and 70 ng/mL. Are you deficient? Quite possibly, as a worldwide study recently found that only Thailand subjects had levels greater than 33 ng/ml. If you are relying on sun exposure as your main source of Vitamin D, 6% whole body exposure in mid day sun provides the equivalent of 600 IU’s of vitamin D. This level drops significantly, from fall to spring.
Symptoms of a Vitamin D deficiency could be an inflammatory disease or condition, osteopenia or osteoporosis, fatigue, or muscle weakness. Since Vitamin D is absorbed in the duodenum, any intestinal disturbances can impair absorption and contribute to a deficiency. So, if you have a condition like Celiac disease, Crohn’s disease, have had gastric bypass, or are obese, your condition might be contributing to a vitamin d deficiency. Vitamin D needs and requirements are also increased during pregnancy and lactation. It is limited in breast milk, and it is therefore recommended to supplement breastfed infants with vitamin d.
Of the most recent discovery in Vitamin d’s benefits is the role it plays in immune modulation. Researchers are beginning to look at the correlation between low winter levels of vitamin D, and increases in infection. Is it possible our yearly dip in vitamin d levels contribute to a decline in immune function and therefore increase the risk of contracting the flu and other viruses? Quite possibly.
What should you do? I recommend all my patients get their Vitamin D levels checked. There is now sufficient data to support the testing and supplementation of Vitamin D. In doing so, you may be doing yourself a favor in preventing many cancers, osteoporosis, chronic pain, and the flu! Of course, when supplementing, it is important to spend your money wisely. Supplements should contain Vitamin D3, or cholecalciferol, and be in gel cap or liquid form for optimal absorption.