Possibly the easiest thing you can do to assure healthy aging is to take a good dose of supplemental vitamin D every day.

The last ten years has brought about a radical change in our knowledge about vitamin D: the many ways it affects physiology, the varied powerful effects on health, the dosage required to produce good results, and the dosage that becomes toxic. We have come a long way from the days when it was believed that everyone needs 400 IU per day and don't even think of taking more or you'll become vitamin D toxic.

The list of conditions vitamin D influences seems to be never-ending. From autoimmune disease to muscle weakness, from obesity to depression, from cognitive impairment to fibromyalgia, vitamin D is a factor. Vitamin D protects against our number 1 killer: heart disease. For one thing, vitamin D inhibits the uptake of oxidized cholesterol by macrophages, a type of white blood cell. This short circuits the process of foam cell formation and plaque build-up in arteries. Vitamin D offers protection from Alzheimer's and Parkinson's diseases.

Vitamin D is probably best known for aiding calcium absorption and building strong bones. It also aids magnesium absorption. Vitamin D regulates the expression of hundreds of genes, influencing immune function, hormone activity, and cell growth. It is a powerful growth suppressor and has been found to protect against many different cancers including breast, colon, ovary, stomach, bladder, prostate, testicle, thyroid, lung, pancreas, as well as Hodgkin's and non-Hodgkin's lymphoma.

One particular study deserves some attention. In a 4 year double-blind, placebo-controlled study of 1179 postmenopausal women some amazing results were obtained. Women who were given 1100 IU of vitamin D and 1500 mg of calcium per day had a reduced incidence of all cancers of 77%! What makes this finding more amazing is that 1100 IU is less than the optimal dose of vitamin D.

Vitamin D is unique among vitamins. In fact, its active form is a hormone, not a vitamin. Our bodies are designed to make our own vitamin D from cholesterol as sunlight hits the skin. Diet supplies little vitamin D. The best natural sources of vitamin D are probably cold-water fish like sardines and salmon. Milk is fortified with vitamin D but the amounts vary from container-to-container and are not adequate.

There is much variability in vitamin D requirements. I had a female patient, deficient in vitamin D, who took one drop a day of Bio D Mulsion, an emulsified vitamin D liquid supplying 400 IU of vitamin D3. A few months later, her vitamin D levels had normalized. Then I had a male patient take the same form of vitamin D3 at 5,000 IU per day. Two months later, his levels were unchanged. We doubled his dose and after two months of 10,000 IU of vitamin D, his levels had barely budged. So, we increased his dose to 20,000 IU a day. This may sound like a lot but there are some individuals who require 40,000 IU per day for several months to achieve normal levels. Why do some people require so much more vitamin D? One reason is obesity. Fat cells "gobble up" vitamin D and make it unavailable to the rest of the body. So, obese individuals tend to need more.  

Dark skin makes less vitamin D. Blacks have lower vitamin D levels. In fact, half of African-Americans with hypertension have it in large part due to vitamin D deficiency. If you don't get out in the sun, you won't make vitamin D. If you're out in the sun but your skin is covered by clothes or by sun-block, you won't make vitamin D. If it is winter and you live at northern latitudes, the sun is too weak for your skin to make vitamin D.

There is a correlation between the altitude people live at as well as the distance from the equator and different health conditions. For example, certain cancers, including lung cancer and autoimmune conditions like multiple sclerosis are less common closer to the equator. Vitamin D status is the factor behind these correlations. Why do influenza outbreaks occur in the winter at Northern latitudes? One reason is that vitamin D levels tend to be lower. Vitamin D helps protect against viral and bacterial infections. In a study of African-American women, one group was given 400 IU of vitamin D per day and the other 2000 IU per day. The group getting 2000 IU per day had almost 90% less respiratory infections through the winter season.

One of the more fascinating studies on vitamin D involved a measure of biological age and vitamin D levels. Individuals of different ages had their blood vitamin D levels measured. They also had measures of white blood cell telomere length. Telomeres are the caps on the chromosomes that protect the DNA from damage. Telomeres shorten with cell divisions and when the telomeres shrink to some critical length, the cells can no longer divide. This study separated people into three groups based on their blood vitamin D levels. It was found that the group with the highest vitamin D levels had longer telomeres- equivalent to 5 years of biological age!

Another study (which was actually a meta-analysis of 18 studies involving 57,311 people) looked at lifespan and vitamin D intake. It found that people taking higher doses of vitamin D had a 7% increase in lifespan.

What dose of vitamin D is optimal? That is something that is very individual and is best guided by laboratory testing. Typical lab reference ranges claim that 30-100 ng/ml are normal. I would recommend more like 50-100 ng/ml for optimal health; maybe more toward the higher side. I had one patient with a vitamin D of 147 ng/ml after supplementation and there was no apparent toxicity. If calcium and parathyroid hormone remain within normal range, the level of vitamin D is likely not toxic. Now without testing, what general guidelines make sense? A recent study found 4000-8000 IU of Vitamin D daily was needed to prevent multiple sclerosis, cancers of the breast and colon, and type 1 diabetes. The same study (Garland C, French C, Baggerly L, et al: Vitamin D supplement doses and serum 25-hydroxyvitamin D in the range associated with cancer prevention. Anticancer Research 2011; 31:607-611.) concluded that doses of vitamin D up to 40,000 IU per day are likely safe. I don't think this should lead us to conclude "more is better". Although most individuals do need to get more vitamin D, at some level cancer incidence is likely to increase along with other adverse effects.  

Vitamin D3 is the preferred supplemental form. Don't take the inferior Vitamin D2. Emulsified Vitamin D is better absorbed. Some "companion" nutrients to consider taking with vitamin D include calcium and the other fat-soluble vitamins: A, E, and K. I recommend testing for all of these. If you don't test, it is probably wise to take some to avoid a condition of imbalance. Designs for Health has a combination vitamin D, A, E, and K supplement. Although it is a good idea to take calcium supplements, you can overdo it. More than 1500 mg per day impairs vitamin D metabolism.

Although more frequent testing is advisable, now is the single best time of year to have your vitamin D levels tested. With shortening days, vitamin D levels will only fall from here. Have your vitamin D measured, supplement if you're low, and retest to assure you are benefiting the most from this critical nutrient.

 Sincerely,

Joseph Debé, DC, DACBN, CDN
Board Certified Nutritionist
38 Great Neck Road
Great Neck, N.Y. 11021
(516) 829-1515
www.drdebe.com