Over 40% of Americans are Dee-ficient.
What Does Vitamin D Do For Us?
Why Is It Called The “Sunshine Vitamin”?
How Much Do You Really Need?
Who Is At Risk For Insufficient Vitamin D?
Which Nutrient Enhances Vitamin D Activity?
How Can You Become A “Light Being”?
TOPIC: VITAMIN D
Why do we feel better when we go out into the sun? Growing evidence suggests that vitamin D regulates the enzyme that converts the amino acid tryptophan into serotonin, a neurotransmitter believed to help regulate mood and direct brain development in utero. Research scientists Rhonda P. Patrick and her mentor, the well-known Bruce N. Ames, uncovered this connection. Initial studies show vitamin D increases serotonin production from 100% – 3000%.
During the past decade, vitamin D has been revealed as something of a miracle. It has been studied more than any other vitamin in the 21st century, and continues to make breaking news. The most recent example being the connection between vitamin D and serotonin production, another reason to call it the “Sunshine vitamin”. (See Topic quote on cover.)
These days, few people get the sun exposure they need to make healthy amounts of the vitamin. Over 40% of Americans are deficient. Within this statistic, over 80% of African Americans and nearly 70% of Hispanic Americans are deficient.
Vitamin D supports healthy immunity and helps regulate cell growth and differentiation. Because of this, researchers speculate that all degenerative disease may be related to vitamin D deficiency. Evidence supporting that speculation was recently revealed by genome research from Oxford University. British and Canadian researchers found over 2700 vitamin D receptors imbedded in our DNA.
The scientists linked vitamin D to genes related to many diseases, including leukemia, colorectal cancer, and regions associated with autoimmune diseases. These discoveries are expected to drive future research.
Low vitamin D levels had already been linked to some cancers as well as to autoimmune diseases, including rheumatoid arthritis, multiple sclerosis, type 1 (juvenile) diabetes, and Crohn’s disease.
Other links include hearing loss and the skin disorders psoriasis and scleroderma. Evidence also indicates that adequate amounts of D protect us against heart disease, diabetes, osteoporosis, periodontal disease, and some mental illnesses. Further, people with epilepsy may need supplementation to replace vitamin D depleted by medication.
Vitamin D Good Day, Sunshine…
The “sunshine vitamin” results from an interaction between the sun’s ultra violet B radiation (UV-B) and undeveloped cholesterol molecules in our skin. The body stores some vitamin D as calcidiol, and later transforms it into activated vitamin D, calcitriol.
Calcitriol (activated vitamin D) is the most potent steroid hormone in the body. (That’s right! “Vitamin” D is actually a steroid hormone.) Active at one trillionth of a gram, this hormone signals the genes to make hundreds of enzymes and proteins crucial to maintaining health and fighting disease. The body’s other steroid hormones (e.g., the adrenal and sex hormones) are manufactured from cholesterol alone, and they are manufactured in the body on demand.
Vitamin D is not made on demand. Exposure to UV-B is essential. No sunshine, no calcitriol. Vitamin D is defined as a vitamin because, as with all the vitamins, it is externally sourced.
The best known biologic role of vitamin D is the maintenance of normal blood levels of calcium and phosphorus. Working with other vitamins, minerals, and hormones, it helps to form and maintain strong bones. When there is not sufficient vitamin D, the bones cannot lay down calcium. This results in the development of the vitamin D deficiency disease. The disease is called rickets in children and osteomalacia in adults.1
Vitamin D Good Day, Sunshine…
1 Rickets involves skeletal deformities, the most typical of which is bowed legs. The adult version also results in weak bones, plus global bone pain, muscle weakness, and muscle pain.
The symptoms of osteomalacia are often misdiagnosed. One common disguise is fibromyalgia. After all, how many doctors would suspect a deficiency of vitamin D?
Vitamin D, Dawn Of A New Day
The discovery of new receptor sites has placed vitamin D in the spotlight. Originally, D receptors for calcitriol were identified in the skin, the small intestine, the bones, and the kidneys.
However, receptors are now known in over 30 additional sites, including the muscles. This information has led to the exploration of the link between vitamin D deficiency and degenerative disease, with some astonishing results.
Bone Up On Sunshine
It is estimated that over 25 million American adults either have osteoporosis or are at risk of developing it. This disease is associated with low calcium intake. However, when there is not enough stored vitamin D, calcium absorption is reduced. Researchers have found higher bone density and fewer fractures in older adults who were given calcium and vitamin D compared with those given a placebo. It is no surprise that a deficiency of vitamin D continues to be associated with a greater incidence of hip fractures.2
In addition, the vitamin D receptors in our muscles respond to sufficient amounts of the vitamin by getting larger. According to an article in NutritionAction, older people with higher vitamin D levels performed better on tests of leg strength. In trials involving more than 1200 older people, vitamin D lowered the risk of falling by 22 percent. This was likewise attributed to stronger muscles. Also, unexplained muscle and bone pain in children and adults has been resolved with vitamin D supplements.
Bone Up On Sunshine
2 Magnesium and vitamin K2 are also necessary to build and maintain strong bones. See Nutrition News, “Healthy Bones For Life”.
Robert Simpson, Ph.D., professor of pharmacology at the University of Michigan Medical School states,
“Vitamin D is now recognized to play a role in heart disease. We’re finding … it’s important for prevention of many of the symptoms … that humans with heart failure experience.”
High blood pressure, a known heart disease risk factor, is associated with problems in metabolizing calcium and with low levels of stored vitamin D. African-Americans have a significantly higher prevalence of HBP and lower vitamin D levels. (Both African-Americans and Hispanics have an inherent difficulty accumulating vitamin D from sunlight. See How Much Sunlight?).
However, both short term daily supplementation with vitamin D and only six weeks of UV-B exposure have resulted in a reduction in blood pressure levels.
Lastly, physical activity is often recommended in the prevention and treatment of heart disease. (Remember, the heart is a muscle.) Besides the benefits of movement, regular physical activity is associated with higher levels of both stored and activated (hormonal) vitamin D.
Daylight & Diabetes
For many years, we have known that normal insulin secretion depends on the presence of vitamin D. Studies show that low vitamin D activity causes both an increase in insulin resistance and reduced insulin secretion.
One recent study revealed that type 2 diabetes is four times more likely in Caucasian Americans with low vitamin D levels than in those with higher levels. The risk for Hispanic-Americans was six fold.
Although African-Americans also participated in this study, the same connection wasn’t found. Researchers commented that most African-Americans have been vitamin D deficient for so long their pancreases are no longer sensitive to it.
As an aside, note that both type 2 diabetes and heart disease are associated with obesity. Research has shown that even with appropriate UV-B exposure or supplementation, vitamin D in obese individuals is 50 percent lower than in the non-obese. Theoretically, this reduced bioavailability is due to calcidiol being deposited in adipose tissue (fat cells) rather than circulating in plasma, making it unavailable for conversion into activated vitamin D (calcitriol).
Sunlight vs Cancer!
Over 60 years of observation have shown an association between high sun exposure and lowered incidence of cancer. Ironic, isn’t it? After years of being warned to avoid the sun because of skin cancer risk, vitamin D researchers are pointing out that the possibility of dying from low vitamin D status is far greater than that of dying from UV-induced skin cancers.
Vitamin D is showing promise with many types of cancer. Researchers have found that 15 minutes a day in the sun can actually lead to the prevention of cancer. A study conducted at the University of California-San Diego and the Moores Cancer Center estimated that 250,000 cases of colorectal and 350,000 cases of breast cancer could be prevented globally by increasing the intake of vitamin D.
Prostate cancer is the leading cancer among men, with one new case diagnosed nearly every two minutes. Researchers at Brigham and Women’s Hospital and Harvard University School of Public Health analyzed the blood of 1029 men with prostate cancer and that of over 1300 healthy men. They found that men with the highest levels of D had significantly lower overall risk of prostate cancer, including the more aggressive types.
There’s sunny news for women too. A Creighton University study of postmenopausal women showed that vitamin D along with calcium supplementation dramatically reduced the risk of developing any cancers by 60 percent.
Shining On Autoimmunity
Autoimmune responses involve immune cells called T-cells.3 Vitamin D can interact with T-cells such that the autoimmune response is diminished. There is evidence for this interaction with type 1 diabetes (juvenile or insulin-dependent diabetes mellitus, IDDM), multiple sclerosis (MS), and rheumatoid arthritis (RA).
Vitamin D deficiency may actually be at cause for the development of both juvenile diabetes and MS. Vitamin D therapy may also be useful to people with lupus (SLE, another autoimmune disease).
Regarding rheumatoid arthritis, the Iowa Women’s Health Study followed almost 30,000 women for over 11 years. During that time, 152 women developed RA. The lowest incidence occurred among women whose diets contained the most vitamin D. Women who got less than 200 IU (the former RDA) were 33 percent more likely to develop the disease.
Shining On Autoimmunity
Put Sunlight In Your Diet
Simply stated, any one of us could be experiencing improved health just by getting enough vitamin D – or, enough sunlight. Which foods are the light carriers?
Vitamin D is fat soluble and is found in fatty foods: egg yolk, skin, organ meats, and fat. Low fat foods just don’t deliver. Years ago, in an effort to prevent rickets, the government ordered that vitamin D be added to milk. There are also enriched breads, cereals, and baby formulas. Testing has shown these products vary widely in their vitamin D content.
When it comes to food, the best bet is cod liver oil. Manufacturing processes add flavorings, leave in the good stuff, and take out the “Ugh!”. A tablespoon contains 1360 IU, which is about twice the new RDA of 600-800 IU. Other rich food sources include pickled herring (680 IU/3.5 oz svg), Eastern oysters (640 IU/svg), and catfish (500 IU/svg). Deep water, fatty fish and organ meats are also on the list.4
Put Sunlight In Your Diet
Footnote 4 The possibility of radiation pollution in the Pacific Ocean from the 2011 Fukushima Daiichi disaster motivated me to do some research. Depending on the source, either fish are already contaminated – or they’re not. I encourage you to take a look for yourself, and consider the sources. Be sure fish are wild caught, and otherwise eat only organic animal products.
In 2010, the Institute of Medicine (IOM) of the National Academy of Sciences established new RDAs for vitamin D supplementation. These are based on age. For people from 1 year to 70 years, the daily dose is 600 IU while for those over 70 the dose increases to 800 IU.
Although 3-4 times the previous RDA of 200 IU, recommendations remain conservative. This is because too much vitamin D can be toxic. However, consider these facts:
1) an article in the American Journal of Clinical Nutrition reports that up to 10,000 IU per day have been taken safely;
2) the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the NIH is launching a longterm study investigating the ability of 4000 IU daily of supplemental vitamin D to prevent the development of type 2 diabetes.
Lastly, consider that light-skinned people can manufacture 20,000 IU of vitamin D in under an hour of sun exposure.
So, what about you? The vitamin D experts in this newsletter suggest ranges from 1000 IU to 4000 IU per day. Robert Heaney, MD, has shown that adequate treatment of vitamin D deficiency requires about 4000 IU per day.
People with autoimmune diseases may be directed to use far higher doses than this. The AJCN article above states that the “lowest observed adverse effect level” (LOAEL) is 40,000 IU per day.
On the other hand, the Food and Nutrition Board of the National Academy of Sciences states that 3800 IU/d (95 mcg) is the LOAEL ever reported. It follows that because individuals have differing reactions to vitamin D supplements, toxic amounts can vary.
Toxicity symptoms include nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Too much supplemental vitamin D can also raise blood calcium levels, causing mental confusion and heart arrhythmia. For now, prudence dictates upper levels of no more than 4000 IU/d, except under the guidance of your health care provider. Be sure to total all the vitamin D in your supplement program, and to purchase only supplemental vitamin D3 (cholecalciferol), not D2 (ergocalciferol).
Incidentally, some older studies led to a concern that vitamin D supplementation could increase an individual’s risk of developing kidney stones. However, a 19 month UCSD study of 2012 participants conducted by Cedric F. Garland, DrPH, and published in the American Journal of Public Health, found no statistically relevant association between vitamin D and the incidence of kidney stones.
Garland commented, “Mounting evidence indicates that a vitamin D serum level in the therapeutic range of 40 to 50 ng/mL is needed for substantial reduction in risk of many diseases, including breast and colorectal cancer.” He added that this serum level is generally only achieved by taking vitamin supplements, advising that
“the best step you can take is to have your serum vitamin D levels measured.” 6
6 Here is one of many websites with information about having your serum vitamin D levels tested: http://www.vitamindcouncil.org/about-vitamin-d/testing-for-vitamin-d/
Are You At Risk From Sunshine?
The most at risk individuals are at either end of the age spectrum: infants and elders.5 An overview of those at risk includes:
- Adults with limited sun exposure
- Children who live in northern regions
- All menstruating women
- Women who are pregnant or breastfeeding
- Babies who are breastfeeding
- Any dark-skinned individuals
- People with inadequate nutritional intake
- Those who abuse alcohol or drugs
- Those on steroid therapy
- Those under prolonged stress
- Anyone recovering from surgery, burns, or injuries
- Anyone missing a portion of their GI tract
- Those who have problems with fat absorption
- Anyone with liver or kidney impairment
- Those with epilepsy
Are You At Risk From Sunshine?
5 Research shows that sufficient vitamin D extends the lives of both the very young and the elderly.
How Much Sunlight?
Our ancestors had the skin pigmentation needed to uptake the right amount of sunshine for where they lived. People living far from the equator developed light-colored skin. Oppositely, dark pigmentation kept those living closer to the equator from getting too much sun.
It takes about an hour of sun exposure for a dark-skinned individual to make as much vitamin D as a light-skinned one makes in 10-15 minutes.
In a perfect world, 90-95 percent of our vitamin D would come from sun exposure. In reality, it is unlikely that we are making as much vitamin D as we need. In addition, aging and obesity both lower the ability of our skin to make vitamin D. Further, a sunscreen with an SPF of only 8 reduces sun penetration by 97 percent.
This does not mean we should seek a deep tan or burn our skin by overexposure (a major cause of about 1.3 million cases of skin cancer annually). The ultimate recommendation is 80-90 percent skin exposure between 10 am and 2 pm several times per week with the time adjusted for pigmentation. At the least, get arms, hands, or back into the sun a couple times a week without sunscreen.7
Once you’ve captured the rays, apply sunscreen. Delay showering 30-60 minutes after exposure. This gives your body time to fully absorb the sunny new vitamin D-enhanced skin oils. The body has self-limiting mechanisms to protect it from manufacturing too much D from sunlight. (Wonderful, isn’t it?)
If you can’t get all the sun implied here, reinforce with D-rich foods and vitamin D supplementation. This is especially important in the winter when UV-B is weaker.
How Much Sunlight?
7 There is a good discussion of the vitamin D and sunscreen dilemma in Don’t Go to the Cosmetics Counter Without Me (9th Edition, 2012), by Paula Beguon, an 1100 page consumers’ report rating products from over 100 cosmetic brands.
Siri Says: Magnesium! Magnesium! Magnesium!
A lot has been said about the importance of taking your calcium with vitamin D. However, research reveals that magnesium is an essential nutrient in the absorption and metabolism of both vitamin D and calcium.
Magnesium actually enhances the body’s use of vitamin D. Called the “orphan nutrient”, magnesium levels are on a downward trend with only 48% of Americans getting sufficient amounts.
Age-related magnesium intakes for adults range from 310-410 mg per day. Common food sources include nuts and beans, especially almonds and soybeans.