Vitamin D – You have been reading about it in the news, and you have wondered what is real and what is hype.
Dr. Myatt and Nurse Mark have researched and prepared this special report for HealthBeat News Readers.
Vitamin D — The Short Course
1.) Vit D is produced in our bodies in response to sun exposure. Vit D is also available from food and supplements.
2.) Vit D is FAR more important to health than was previously realized. I’m talking FAR more important.
3.) Vit D deficiency is widespread, including North America, even in sunny climates like Arizona. Many people who think they are getting enough Vitamin D from sunlight are mistaken.
4.) How to Optimize Vit D Levels for Good Health:
I.) Vit D test, supplement accordingly, re-test
II.) Supplement at 5,000IU for 3 months, then test your levels.
III.) Don’t test, run the risk of being deficient, but take at least 2,000IU total per day. (This is still an extremely conservative dose, but much higher than the RDA of 400IU which hasn’t been changed yet to reflect the newer findings about Vit D).
5.) Natural ways to obtain Vit D: Foods, supplements and sun exposure.
Vitamin D — Nutrient of the Decade: Are You Getting Enough?
The Consequences of Low Vitamin D
Vitamin D is called “the sunshine Vitamin” because our bodies make it in response to sun exposure.
Vit D is necessary for normal bone formation in both children and adults. In children, deficiencies of Vit D lead to rickets. In adults, deficiencies are associated with osteoporosis and osteomalacia (soft bones), decreased muscle strength and increased risk of fall. (1,12,14,22,43-48)Until recently, the bone-protecting effect was about all that Vit D was known for, but the past decade of medical research has changed all that.
The newly appreciated Vitamin D deficiency risks include:
1.) heart disease: myocardial infarction, high blood pressure, heart failure, myopathy, sudden cardiac death, stroke (11,13-26, 30, 49-50)
2.) blood sugar problems: glucose intolerance, diabetes mellitus, metabolic syndrome (13-14,19,23-24,27-29)
3.) cancer prevention and improved cancer survival rates (7,8,11,14,15,24,31-37)
4.) upper respiratory tract infections, influenza and tuberculosis (24,30,38)
5.) cognitive impairment and low mood (38-40)
6.) autoimmune disease (multiple sclerosis, RA, systemic lupus erythromatosis (SLE) (15,24,26,29,30,32,41,42)
7.) misc. diseases: psoriasis, polycystic ovarian syndrome, inflammatory bowel disease
8.) urinary incontinence (54)
9.) and all-cause mortality! (5,6,7,24,30,51)
How “significant” are these associations? Here are some of the conclusions of various studies and meta-analyses (lots of studies looked at together) concerning Vit D. Italics are mine for emphasis.
“Research strongly supports the view … Vitamin D status would have significant protective effects against the development of cancer …. cancers of the breast, colon, prostate, ovary, lungs, and pancreas…” (8)
“High levels of Vitamin D among middle-age and elderly populations are associated with a substantial decrease in cardiovascular disease, type 2 diabetes and metabolic syndrome.” (9)
“Low levels of [Vitamin D] are independently predictive for fatal strokes” (10)
“It is estimated that there is a 30 to 50% reduction in risk for developing colorectal, breast, and prostate cancer by either increasing Vitamin D intake or increasing sun exposure…” (11)
“Oral Vitamin D supplementation between 700 to 800 IU/d appears to reduce the risk of hip and any nonvertebral fractures in ambulatory or institutionalized elderly persons” (12)
” 28 studies including 99,745 participants … highest levels of serum [Vit D] were associated with a 43% reduction in cardiometabolic disorders (cardiovascular disease, diabetes and metabolic syndrome) …” (9)
Are Your Vitamin D Levels Optimal? (Vitamin D Deficiency is Widespread)
One billion people worldwide are estimated to be Vit D deficient, and the problem affects us here in the United States as well. (2) One study found that more than half of North American women receiving drugs for prevention or treatment of osteoporosis were Vitamin D deficient. (1) Another study found 48% of pre-adolescent girls to be Vit D deficient (3). Other studies have found that 40% to 100% of older men and women in both the United States and Europe are Vitamin D deficient.[2] Because of the importance of Vit D and how widespread Vit D deficiency is, an estimated $100 to $200 billion is spent (wasted) each year on diseases which may really just be Vitamin D deficiencies. [4]
Age, overweight, dark skin color, use of sunscreen, and overprotection from the sun’s rays are causes of decreased production of Vit D in response to sunlight. (52,52)
How Much Vitamin D Should You Take?
Ideally, you should take whatever amount of Vitamin D puts you in the “optimal” range. Since the amount will be highly variable depending on age, sex, race, weight, daily sun exposure and diet, there is no “one size fits all” answer. Instead, blood testing of Vitamin D levels and increasing intake until optimal levels are reached is the surest way to obtain optimal concentrations of Vitamin D in the body.
Deficiency Insufficiency Sufficiency * Optimal Excess (Toxicity) <20ng/ml 20-32ng/ml 32-100ng/ml 40-80ng/ml > 150ng/ml
* – conventional medicine says that 30 ng/ml is “sufficient.” Chart references (59-62)
At the wellness Club we believe the most accurate and effective way to embark on a program of Vit D supplementation is to perform a Vit D test, supplement Vit D in accordance with the results, and then re-test in 3 months at which time your daily doses of Vit D can be fine-tuned for maintenance. March (right now!) is the best time to test initially because Vit. D stores tend to be lowest in this month.
The Vitamin D Council, a non-profit group dedicated to Vitamin D research and education recommends people take 5,000 IU per day for 2-3 months, then perform a Vitamin D test. They then suggest adjusting the dosage so that blood levels are between 50-80 ng/mL (or 125-200 nM/L) year-round. (55)
Alternately, some people opt to supplement without knowing their initial Vit D levels. A dose of 2000IU is quite conservative but certainly safe for almost anyone. In cases of significant Vit D deficiency conservative dosing such as this may take considerable time to rebuild healthy stores of this important Vitamin.
For those who wish to calculate their own Vit D requirements, 100 IU of Vitamin D could be expected to raise blood level of 25(OH)D by 1 ng/ml. (11)
Can too much Vitamin D can be toxic? Research shows that massive doses may eventually cause toxicity. One source found that in adults a sustained intake of 50,000 IU daily could produce toxicity within a few months (58) and 40,000 IU per day in infants has been shown to produce toxicity within 1 to 4 months. (56) That is ten times the recommended dose for each of those age groups! Vitamin D testing is good insurance that will allow you to safely fine-tune your dosage to your actual needs. Be careful though, since not all testing is the same and lab references and standards vary – be sure that you are comparing “apples to apples” and obtaining useable results when you are tested.
The 25-hydroxyVitamin D blood test (25(OH)D blood test) is a test that measures the amount of calcidiol circulating in the blood. This is the most accurate measure of the amount of Vitamin D in the body. The Wellness Club offers Vitamin D testing – performed by a lab that adheres to standardized references and values so that you know what you are getting when you receive your results. This can is performed at home with a “spot” (finger stick) blood test. Other tests that require a blood draw are also available.
How to Get to Your Optimal Vitamin D Levels
Start Vitamin D supplementation eight to twelve weeks before testing. Dr. John Cannell of the Vitamin D Council suggests a starting dose of 1,000 IU per 25 pounds of body weight. For example, a 150 pound person would take 6,000 IU Vitamin D per day. (150 divided by 25 = 6; 1,000IU x 6 = 6,000). Maintain this dose for 8-12 weeks, then test.
This dose may or may not put you in the optimal target range, but it certainly won’t put you in any “toxic” range. Remember, most adults can safely take up to 10,000IU per day and still be far away from Vitamin D toxicity which typically appears at 40,000-50,000IU taken for several months.
Although this dose should theoretically put you in an optimal range, numerous personal variations alter Vitamin D requirements. Some people will need a higher dose than this calculation affords. However, taking the calculated dose should at least put you “in the ballpark” for optimal dosing.
When you test results come back, you can use the number to help you know whether or not you need to increase your Vit D dose and by how much. It is estimated that each 1,000 IU increase in supplemental Vitamin D will generally produce a 10 ng/ml increase in the Vitamin D blood level (8). If your test result shows that you are 10ng/ml below your target, increase daily Vit D intake by 1,000IU per day for a total of 7,000IU per day from the above example. Continue this dose and re-test in another 3 months to verify that you are now in your optimal range.
Congratulations! You have found your optimal daily Vitamin D intake needed to maintain optimal Vitamin D blood levels.
How to Obtain Vitamin D Naturally
Exposure to sun is the most natural way to boost Vit D levels. Medical scientists have found that the skin produces approximately 10,000 IU of Vitamin D in response to as little as 30 minutes of unprotected summer sun exposure. (57)
Vitamin D can be obtained from food too. Since rickets in children is such a crippling but preventable condition, governments have long encouraged the “fortification” of dairy products and breads and cereals with token amounts of Vitamin D. In the United States and Canada, for example, fortified milk typically provides 100 IU per glass.
It is difficult to obtain optimal levels of Vitamin D from food alone.
Food IUs per serving* Percent DV** Cod liver oil, 1 tablespoon 1,360 340 Salmon (sockeye), cooked, 3 ounces 794 199 Mushrooms that have been exposed to ultraviolet light to increase vitamin D, 3 ounces (not yet commonly available) 400 100 Mackerel, cooked, 3 ounces 388 97 Tuna fish, canned in water, drained, 3 ounces 154 39 Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup 115-124 29-31 Orange juice fortified with vitamin D, 1 cup (check product labels, as amount of added vitamin D varies) 100 25 Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces (more heavily fortified yogurts provide more of the DV) 80 20 Margarine, fortified, 1 tablespoon 60 15 Sardines, canned in oil, drained, 2 sardines 46 12 Liver, beef, cooked, 3.5 ounces 46 12 Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40 10 Egg, 1 whole (vitamin D is found in yolk) 25 6 Cheese, Swiss, 1 ounce 6 2 *IUs = International Units.
**DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents of products within the context of a total diet. The DV for vitamin D is 400 IU for adults and children age 4 and older. Food labels, however, are not required to list vitamin D content unless a food has been fortified with this nutrient.
Table courtesy of the U.S. Government National Institutes of Health Office of Dietary Supplements
Although cod liver oil is high in Vitamin D, it is also high in Vitamin A which interferes with Vit D uptake, so cod liver oil is not the best supplemental form of Vit D. Keep daily intake of pre-formed Vitamin A to a maximum of 5,000IU per day so as not to interfere with Vitamin D absorption. Beta carotene does not appear to interfere with Vit. D uptake.
Vegetarians need to be sure they are getting plenty of sunshine, because other than tiny amounts that may be found in UV-irradiated mushrooms, there are no vegetable sources of Vitamin D.
The Bottom Line on Vitamin D
Achieving Optimal Vitamin D levels appears to be one of the most important things we can do for our overall health and life expectancy.
Please click on the image below enjoy an interesting and instructive video which discusses the relationship between Vitamin D and Cancer.
References
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