The ABC’s of Vitamin D
As I write this, the sun is shining and the temperature reads 70 degrees. Although I am inside, I probably should be outside in short sleeves getting my daily dose of vitamin D. Vitamin D has been the subject of a tremendous amount of research in the past decade. Molecularly, vitamin D is closer to being a steroid than a vitamin and resembles cholesterol in structure. Most people understand that the sun stimulates the skin to produce vitamin D; the cultural norm that encourages avoidance of the sun through use of long sleeves and sun block has led to a chronic deficiency of vitamin D. While I understand the risks associated with sunburns, I feel that direct daily sun exposure is essential for health, and I am especially concerned about the compulsion to use conventional sun screens, which contain carcinogenic constituents. It has been estimated that the RDA of vitamin D (a paltry 200 IU for adults) can be synthesized with the exposure of 30% of a person’s skin for 30 minutes at Oregon’s latitudes.
Vitamin D plays a major role in bone metabolism by facilitating the absorption of calcium and phosphorus in bone mineralization. It regulates the release of parathyroid hormone, which pulls calcium from the bones to raise blood levels. It plays a role in muscle function, nerve function and plays a role in proper immune function. There is also research supporting its role in the treatment of diabetes, multiple sclerosis and cardiovascular disease. It also is critical for proper control of cell division and cell repair, making it a critical nutrient for cancer patients. Some researchers believe that Vitamin D deficiency could be associated with half of all cancers. It is involved with at least twenty genes that determine cell proliferation, differentiation and apoptosis (natural cell death) and there are at least eighteen cancers, especially colorectal cancers and hormonal cancers (e.g. breast and prostate cancer) that it may help to prevent and inhibit.
The best food source of Vitamin D is cod liver oil, which delivers 1300 IU per tablespoon, or about 30-80% of what I recommend for the average patient per day. There are brands available that offer cod liver oil that does not have a strong odor or taste. Cod liver oil is also high in Vitamin A (about 1500 IU per tablespoon) as well as Omega 3 oils (over 2000 mg). Bone broth made from the bones of these fish not only will yield vitamin D, but will provide a source of calcium, phosphorus, magnesium, and potassium, all in forms that your body can easily absorb. As discussed below, these are all necessary nutrients for the absorption of vitamin D. Sardines and mackerel also provide high doses. And the food with the highest levels of vitamin D? Halibut liver, at 16,800 IU per 100 grams!
Vitamin D should be taken with calcium, magnesium, vitamin A and vitamin K. Doing so not only assists with proper absorption but also assimilation into bones. Some studies indicate that without these nutrients, patients are more likely to develop atherosclerosis (hardening of the arteries) or kidney stones, probably due to excessively high calcium levels. There has been considerable debate about the role of vitamin A in conjunction with vitamin D; the problem lies in the fact that taking high vitamin A in patients who are deficient in vitamin D can actually interfere with vitamin D assimilation. I generally recommend on supplementation in a 1:5 ratio of A to D. If you are taking Vitamin D for proper bone health (perhaps you have been diagnosed with osteopenia or osteoporosis), it is worth asking your doctor to perform a simple test that will allow him or her to deduce your vitamin K status. This test assesses the activity of osteocalcin, the primary bone building protein. 1/4 to 1/3 of women tested have low activity of this protein. Because vitamin K activates osteocalcin, it is imperative that those who have low osteocalcin activity take vitamin K with vitamin D.
Prednisone and Dilantin (an anti-seizure medication) both interfere with vitamin D absorption. Those who are on these medications should also be on vitamin D. Regardless of your reason for supplementation, consult a doctor! Excessive vitamin D can be toxic, so testing should be done regularly.
One last point regarding sunscreen lotion: I recommend avoiding it if at all possible. It is interesting that people who are very concerned about what they put intheir bodies are not at all apprehensive about what they put ontheir bodies! I have found sunscreen lotion to be unnecessary. My advise is to slowly increasing your bare skin to the sun you will soon acclimate without burning. Start with 15 minute per day for one week and increase each week by increments of 15 minutes. 2-3 hours of beach time exposure to the sun (without sunscreen) can yield up to 20,000 IU of vitamin D!
Dr. Daniel Smith practices at Bear Creek Naturopathic Clinic. His office is on 2612 Barnett Rd. He specializes in naturopathic oncology, but still maintains a strong family practice, treating all manner of conditions. He can be reached at 541-770-5563 or at email@example.com If you would like to schedule an appointment, please ask specifically for Dr. Dan.