The Sunshine Vitamin
By Dr. Mercola
How much vitamin D do you need?
Vitamin D, often referred to as "the sunshine vitamin," is different from other vitamins in that it influences your entire body. Receptors that respond to vitamin D have been found in almost every type of human cell, from your brain to your bones.
Optimizing your vitamin D levels could help you to prevent as many as 16 different types of cancer including pancreatic, lung, breast, ovarian, prostate, and colon cancers.
In fact, a previous landmark study from the Moores Cancer Center at the University of California, San Diego (UCSD) found that some 600,000 cases of breast and colorectal cancers could be prevented each year, if only vitamin D3 levels among populations worldwide were increased.
Beyond cancer, the researchers pointed out that increasing the levels of vitamin D3 could prevent diseases that claim nearly 1 million lives throughout the world each year! Other studies showed that you can decrease your risk of cancer by more than half simply by optimizing your vitamin D levels with sun exposure.
Further, optimal vitamin D levels are also known to positively influence the following conditions:
- Heart disease
- Inflammatory bowel disease
- Rheumatoid arthritis
- Multiple sclerosis and osteoporosis
How much vitamin D do you need?
Your doctor can measure your serum 25-hydroxyvitamin D (25(OH)D) to determine your vitamin D status. Your vitamin D level should never be below 32 ng/ml (meaning nanograms – one billionth of a gram – per mililitre, a standard unit of clinical measurement), and anything below 20 ng/ml is considered a serious deficiency state, which will increase your risk of breast and prostate cancers and autoimmune diseases like multiple sclerosis and rheumatoid arthritis.
In Canada (focusing on the lower latitudes where most cities are located), late winter 25-hydroxyvitamin D levels generally range from 15 to 18 ng/ml, so vitamin deficiency affects a very large portion of the population.
The optimal value that you're looking for is 45 to 52 ng/ml, but previous research has suggested that maintaining a slightly higher level of 55 ng/ml (nanograms per millilitre) is optimal for cancer prevention.
African Canadians are even more prone to vitamin D deficiencies because they produce less vitamin D3 than do Caucasians in response to usual levels of sun exposure and, therefore, have lower vitamin D serum concentrations year-round. In fact, as many as 42 percent of black Canadian women, compared to just over 4 percent of white women of childbearing age, have serum concentrations that are deficient even during the summer months.
RDA too low for achieving optimal vitamin D levels
The latest study published in the American Journal of Clinical Nutrition points out that some North Americans simply cannot reach optimal vitamin D levels under the current recommended daily allowance (RDA) guidelines. The 1997 Panel on Calcium and Related Nutrients considers 2,000 IUs (international units) as the upper limit of intake, with a recommended daily allowance of just 400 to 600 IUs per day.
In fact, the new dosing algorithm that this study proposes calls for a daily dose of 2,800 IU s for those individuals with an adequate serum level, and 4,000 IUs per day if your serum level is measured as too low. In addition to this, the study points out that given the individual variability in your response to vitamin D, the best result would be expected if your 25 (OH)D was measured and your dose of vitamin D is adjusted a second time.
I also recommend you check your vitamin D levels regularly because overdosing on oral vitamin D supplements is possible. (There's very little risk of overdosing on vitamin D from the sun, however.)
What is your best source of vitamin D?
Sun exposure (without sunscreen) of about 10 to 15 minutes a day, with at least 40 percent of your skin exposed is your best source of vitamin D. Sometimes, however (such as if you happen to live in rainy or cloudy areas), you may not be able to get enough sun exposure during certain parts of the year. In that case supplementation is an option. Obviously, it is very difficult for many of us to get adequate sun exposure in the winter, which is why I also advise using a safe tanning bed to have your own body produce vitamin D naturally.
The most important thing to keep in mind if you opt for oral supplements is that you only want to supplement with natural vitamin D3 (cholecalciferol), which is the type of vitamin D found in foods like eggs, organ meats, animal fat, cod liver oil and fish. Do not use the synthetic and highly inferior vitamin D2.
To find out more about the crucial importance of sunlight and vitamin D for your health, my forthcoming book Dark Deception will explore this topic in detail, and expose why the conventional wisdom on the subject, which encourages you to stay out of the sun, is dead wrong.
Discover the new innovative system that combines the best in vitamin D-producing, tanning, and healthy skin support all in one!
About the guest author:
Dr. Mercola, the New York Times best-selling author, has helped countless people to reach their health and weight loss goals. An osteopathic physician, board certified in family medicine, Dr. Mercola is passionate about empowering people to take control of their health using solely natural means.
Dr. Mercola's natural health Web site, www.Mercola.com, has been the most visited natural health site on the Internet, with over 12 million page views every month. More than 1 million people subscribe to Dr. Mercola's free e-mail newsletter, which has been in circulation since 1998.
Shelly Lynn Miss British Columbia 2001 Lightweight, and a member of the CHFA Sports Nutrition Advisory Council.
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