Optimizing your vitamin D level may be one of the most important steps you can take in support of your long-term health.  Another article is needed to describe its many beneficial effects, but here we’ll simply focus on how to make sure you’re getting the ideal amount of vitamin D.

Perhaps the best way to optimize your vitamin D level (although not always possible or convenient) is by exposing a large area of skin to sunlight when the sun is highest in the summer sky, around noon. It takes about 15 minutes of this exposure to produce upwards of 10,000 IUs of vitamin D. Always stop well before any burning can occur and build up to it gradually, even starting with just a few minutes. As the sun drops below 50 degrees from the horizon in the winter sky, the UV-B rays that catalyze the production of vitamin D are blocked by the density of the atmosphere. Of course you can still sunburn in the winter from the UV-A rays that are able to penetrate even the clouds and window glass, but no vitamin D will be made. At our latitude in Eugene, our window of opportunity to make vitamin D from the sun is from early April until early September, and only from 11 AM to 1 PM.  If you opt to use a tanning bed, be sure that you are receiving UV-B rays, and go easy with it. The point is to make vitamin D and take advantage of the many other health benefits of UV light, not fry your skin for a dark tan. Vitamin D is fat soluble and is stored in the body over time. The “half-life” of any summer vitamin D storage is about 6 weeks. So, by 12 weeks into the winter we have one quarter of our summer stores, and one eighth in another 6 weeks. By the time we get to the flu season of early spring we have hit rock bottom of our vitamin D stores, unless we’ve been supplementing with vitamin D.

It’s important to understand the difference between the two types of vitamin D available in supplement form. Research comparing synthetic vitamin D2 supplements versus natural vitamin D3 shows that vitamin D3 is approximately 87 percent more potent in raising and maintaining vitamin D concentrations, is converted into its active form 500 percent faster, produces 2 to 3-fold greater storage of vitamin D than does D2, and has health benefits that the D2 form lacks. The vitamin D available at this office is the D3 form, derived from sheep wool lanolin. It is thus safe for vegetarians. Plant-based food sources that contain vitamin D provide vitamin D2. Only animal-based food sources, such as fish, egg yolk, and raw milk, naturally contain D3. Of course, Vitamin D can be made by our body from a derivative of cholesterol, catalyzed by the ultraviolet rays of the sun under the conditions described above.

The most important consideration is not the dosage but rather your vitamin D serum level, which should ideally be between 50-70 ng/ml.  When taking an oral vitamin D supplement, you should take enough to reach and maintain this therapeutic level. Without supplementing vitamin D, most people here are clinically deficient, with blood levels commonly testing in the 20’s. The average daily amount needed by an adult to optimize their serum level seems to be about 5000 IU. However, it’s important to recheck your vitamin D level with a blood test after taking this amount for 2 to 3 months. Although this is average, a few people seem to maintain good blood levels with as low as 2000 IU per day, and some definitely need 10,000 IU. With blood testing over time you can hone in to your individual need. If you want your vitamin D tested by your family physician, be sure that the test ordered is 25(OH)Vit D3, read as “25 hydroxy vitamin D3”. We can provide blood testing at this clinic as needed.

Vitamin D3 is inexpensive and readily available at any health food store as well as this clinic.  Sometimes people are “prescribed” 50,000 IU of vitamin D3 or D2 once a week by their medical doctor. In my opinion, the body responds better to smaller consistent amounts that mimic nature as much as possible. Since our bodies are capable of producing vitamin D in the 5000 to 10,000 IU range daily, I recommend that we supplement in this manner for long term health. For short term use to stop a cold or flu, there has been some anecdotal evidence that taking 50,000 IU daily for about 3 or 4 days can help. No harm in trying this, as toxicity is very rare and could occur only with prolonged intake (months) of far greater amounts (many hundreds of thousands of IU’s). But I still prefer to stay within the parameters of nature if possible and maintain health rather than trying to fight disease.

Be aware that if you are taking an optimum amount of supplemental vitamin D, you also need to get enough vitamin K2, as these two nutrients work in tandem. Vitamin K2 deficiency is actually what produces the symptoms of vitamin D toxicity, which includes inappropriate calcification that can lead to hardening of your arteries. Vitamin D makes calcium available to the body via the blood stream, but vitamin K2 completes the process by directing the calcium into the bones and out of areas where it doesn’t belong such as calcific arterial plaques. The current medical recommendation to take vitamin D and large amounts of calcium for the bones may have the unfortunate effect of causing cardiovascular problems if it excludes the K2. By taking both vitamin D and K2, you help prevent osteoporosis, arteriosclerosis and hardening of the arteries. To increase the absorption of both vitamin D and K2, it’s best to take them with the largest meal of the day, or with some fat content, since they are both fat soluble vitamins.

While the ideal or optimal ratios between vitamin D and vitamin K2 have yet to be elucidated, Dr. Kate Rheaume-Bleue, author of Vitamin K2 and the Calcium Paradox: How a Little Known Vitamin Could Save Your Life, suggests that for every 1,000 IU's of vitamin D you take, you may benefit from about 100 micrograms of K2, and perhaps as much as 150-200 micrograms (mcg). There are 2 forms of vitamin K2: The MK-4 form is synthetic, requires larger dosages, and is quickly absorbed but doesn’t stay in the system long, so should be taken in split dosages during the day. European research showed reversal of osteoporosis by taking 15 milligrams three times a day of the MK-4 form. The MK-7 form is found naturally in fermented foods such as Japanese Natto, circulates in the blood for longer periods and only requires microgram dosages to be effective. In this clinic we have 15 mg capsules of the MK-4 form for special purposes such as osteoporosis, and a mixed MK-4 and MK-7 vitamin K2 capsule for general use.

Besides enjoying the summer sun appropriately, I commonly recommend the daily use of one capsule of vitamin D 5000 IU and 1-2 capsules of the mixed vitamin K2;  then checking the serum level of vitamin D after a couple of months. Once you’ve established your individual need, it’s good health insurance to continue using these basic nutrients for the long haul.