Alzheimer's disease, sun, vitamin DThere are several risk factors for the development of Alzheimer’s disease and vascular dementia. An increasing number of studies link these risk factors with vitamin D deficiency. Dr. William B. Grant of the Sunlight, Nutrition, and Health Research Center (SUNARC) suggests that further investigation of possible direct or indirect linkages between vitamin D and these dementias are needed.

Low serum levels of 25-hydroxyvitamin D have been associated with increased risk for cardiovascular diseases, diabetes mellitus, depression, dental caries, osteoporosis, and periodontal disease, all of which are either considered risk factors for dementia or have preceded incidence of dementia.

For example, several studies have correlated tooth loss with development of cognitive impairment. There are two primary ways that people lose teeth: dental caries and periodontal disease. Both conditions are linked to low vitamin D levels.

Additionally, as reported by Reuters, low levels of vitamin D are also associated with the loss of cartilage in the knee joint of older individuals. Cartilage loss is the hallmark of osteoarthritis.

The researchers found that osteoarthritis patients with vitamin D sufficiency have approximately 1.5 percent less loss of knee cartilage per year than patients with vitamin D deficiency. The investigators measured the levels of vitamin D in blood samples, as well as the knee cartilage volume on X-rays, of nearly 900 men and women. The team then took similar measurements again almost three years later for about 350 of the study participants.

Overall, 58 percent of these subjects showed changes in knee cartilage indicating worsening osteoarthritis. But both at the beginning of the study enrollment and at follow up, men and women with vitamin D deficiency had lower knee cartilage volume and were more likely to experience knee pain.

Vitamin D Dose Recommendations
Age Dosage
Below 5 35 units per pound per day
Age 5 – 10 2500 units
Age 18 – 30 5000 units
Pregnant Women 5000 units
There is no way to know if the above recommendations are correct. The ONLY way to know is to test your blood. You might need 4-5 times the amount recommended above. Ideally your blood level of 25 OH D should be 60ng/ml.


Vitamin D was once linked to only bone diseases such as rickets and osteoporosis but now is recognized as a major player in overall human health.

One of the most exciting benefits of vitamin D that is still being uncovered is its impact on your brain. As Dr. William Grant, one of the top vitamin D researchers in the world, pointed out, observational studies support a beneficial role of vitamin D in reducing the risk of diseases linked to dementia, such as vascular and metabolic diseases, as well as an understanding of the role of vitamin D in reducing the risk of several factors that lead to dementia.

How Might Vitamin D Benefit Your Brain … and Alzheimer’s Disease?

Scientists are beginning to realize vitamin D is involved in maintaining the health of your brain, as they’ve recently discovered vitamin D receptors in your brain, spinal cord, and central nervous system. (In fact, there are 36 organ tissues in your body whose cells respond biologically to vitamin D, including bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach and uterine tissues.)

There are actually only 30,000 genes in your body and vitamin D has been shown to influence over 2,000 of them. That is one of the primary reasons it influences so many diseases from cancer and autism to depression and asthma.

But getting back to its role in brain health, in 2007 researchers at the University of Wisconsin uncovered strong links between low levels of vitamin D in Alzheimer’s patients and poor outcomes on cognitive tests.

Scientists launched the study after family members of Alzheimer’s patients who were treated with large doses of prescription vitamin D reported that they were acting and performing better than before.

Researchers believe that optimal vitamin D levels may enhance the amount of important chemicals in your brain and protect brain cells.

Just recently researchers from the University of Manchester also found that getting more vitamin D helps elderly people stay mentally fit. Researchers compared the cognitive performance of more than 3,000 men aged 40 to 79, and found those with low vitamin D levels performed less well on a task designed to test mental agility.

Further, the brain benefits of vitamin D have also been described in several experimental models, indicating the potential value of vitamin D in helping neurodegenerative and neuroimmune diseases. In addition, vitamin D induces glioma (a type of tumor) cell death, making the hormone of potential interest in the management of brain tumors.

There’s even evidence indicating vitamin D improves your brain’s detoxification process. For children and pregnant women, getting enough vitamin D is therefore especially crucial, as it may play a major role in protecting infants’ brains from autism.

Even More Benefits of Vitamin D

The second study mentioned in the above article found a promising link for the role of vitamin D in helping to prevent knee osteoarthritis (a degenerative joint disease).

Those in the study with vitamin D deficiency had lower knee cartilage volume and were more likely to experience knee pain. It’s thought that vitamin D plays an important role in cartilage changes, and vitamin D deficiency may predict knee cartilage loss over time.

So if you are currently struggling with knee pain, joint pain or osteoarthritis, adding regular sun exposure to your lifestyle, and supplementing with a high-quality source of vitamin D when this is not possible, may help.

The Best Source of Vitamin D, and What Level You Need to Stay Healthy

Exposing your skin to sunlight is the best way to get vitamin D.

Sun exposure (without sunscreen) until your skin turns the lightest shade of pink is a general guide of how much you need. For some, this will be about 10 to 15 minutes a day, with at least 40 percent of your skin exposed, although people with dark skin will need to stay out significantly longer. Please read this past article for a list of safe tanning guidelines.

If you’re able to get out in the sun for an adequate time period each day, your vitamin D levels should be naturally optimized.

However, most of us have days during which we may not be able to get enough sun exposure, either due to weather or time constraints. In that case, I also advise using a safe tanning bed (one that has the harmful emissions shielded) to have your own body produce vitamin D naturally.

A third option is taking a high-quality vitamin D supplement. The most important thing to keep in mind if you opt for oral supplementation is that you only want to supplement with natural vitamin D3 (cholecalciferol), which is human vitamin D. Do NOT use the synthetic and highly inferior vitamin D2.

How do you know if you’re getting the right amount of vitamin D?

You need to have your blood levels tested, but not just any test — or any lab — will do.

I’ve discussed exactly what you need to know to get the right vitamin D test, with accurate results, here. The OPTIMAL level of vitamin D you’re looking for is 50-65 ng/ml.

For even more information on vitamin D, including how to use it for the greatest health benefits, please watch my free one-hour vitamin D lecture.

More Natural Tips for Preventing Alzheimer’s Disease

Given that approximately 10 million American baby boomers will develop Alzheimer‘s disease in their lifetime, and by 2010 there will be 500,000 new cases each year, starting on prevention strategies now is of utmost importance.

These simple lifestyle changes can help keep your brain in optimal working order now and as you get older.

  • Optimize your vitamin D levels through safe sun exposure, a safe tanning bed and/or vitamin D supplements.
  • Eat a nutritious diet with plenty of vegetables based on your nutritional type, and pay special attention to avoiding sugar.
  • Eat plenty of high-quality, animal-based omega-3 fats in the form of krill oil. Avoid most fish (high in omega-3, but often contaminated with mercury).
  • Avoid and remove mercury from your body. Dental amalgam fillings are one of the major sources of mercury, however you should be healthy prior to having them removed. Once you have adjusted to following the diet described in Take Control of Your Health, you can follow the mercury detox protocol and then find a qualified biological dentist to have your amalgams removed.
  • (Be sure to only use a high-quality biologically trained dentist who is familiar with the removal of amalgam fillings or your health could get ruined.)

  • Avoid aluminum, such as in antiperspirants, cookware, etc.
  • Exercise for three to five hours per week. According to one study, the odds of developing Alzheimer’s were nearly quadrupled in people who were less active during their leisure time, between the ages of 20 and 60, compared with their peers.
  • Avoid flu vaccinations as they contain both mercury and aluminum!
  • Wild blueberries, which have high anthocyanin and antioxidant content, are known to guard against Alzheimer’s and other neurological diseases.
  • Challenge your mind daily. Mental stimulation, such as traveling, learning to play an instrument or doing crossword puzzles, is associated with a decreased risk of Alzheimer’s. Researchers suspect that mental challenge helps to build up your brain, making it less susceptible to the lesions associated with Alzheimer’s disease.

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