Can vitamin D and Sunlight make you smarter?

The preponderance of evidence suggests that higher blood levels of vitamin D correlate to better cognitive ability (ability to think), so if you want a higher IQ, it behooves you to keep your vitamin D levels high. In the winter in the Northern US, Northern Europe, Canada and other high-latitude countries, this may mean supplementing with 3,000-5,000 IU daily for most people and up to 6,400 IU daily for nursing mothers.[1] Another alternative is to use a tanning bed two or three times weekly or take frequent tropical vacations (unless you have type-one skin that does not tan—never burn).

The latest scientific paper on cognitive abilities as compared to vitamin D levels shows that persons who have the lowest levels are more than twice as likely to be cognitively impaired as those with the highest levels.[2] I was not surprised at the results of this study; in my book, I had documented other research indicating that in elderly people with the highest levels of vitamin D scored 3-5 times higher on two cognitive tests than those with the lowest levels.[3] Those with the lowest levels were also 12 times as likely to be depressed.

When we consider that vitamin D is absolutely essential to proper nerve function and development,[4] [5] and that there are vitamin D receptors throughout the central nervous system,[6] it stands to reason that mental abilities would be compromised by poor vitamin D status. It also follows that depression would be higher in those whose levels are low. Therefore, it follows that sunlight and vitamin D may make you both smarter and happier.

[1] Wagner C. et al. High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study. Breastfeed Med 2006;1:59-70.
[2] Llewellyn, D. et al. Serum 25-Hydroxyvitamin D Concentration and Cognitive Impairment. J Geriatr Psychiatry Neurol Online. December 10, 2008.
[3] Wilkins C. et al. Vitamin D Deficiency Is Associated With Low Mood and Worse Cognitive Performance in Older Adults. Am J Geriatr Psychiatry;2006;14:1032–1040).
[4] McCann J. et al. Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain
dysfunction? FASEB J. 2008;22:982-1001.
[5] Carlson, A. et al. Is vitamin D deficiency associated with peripheral neuropathy? The Endocrinologist 2007;17:319-25.
[6] McCann J. et al. Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain
dysfunction? FASEB J. 2008;22:982-1001.

Does Vitamin D help prevent Type-one Diabetes?

A new study shows that most type-one diabetic children have low levels of vitamin D.[1] Dr. Lori Laffel, senior author or the research, expressed surprise that only 24% of the children studied had adequate levels. The researchers then suggested that the children be supplemented with 400 IU daily.

What makes this research and its recommendations so interesting is that it is already established that supplementing 2,000 IU per day in children correlates to an 80% reduced risk of type-one diabetes.[2] Why the surprise? Do these people read the research? Type-one diabetes is an autoimmune disease. In my book, I thoroughly cover the research showing that vitamin D is exceptionally effective in reducing autoimmune disorders. A study like this one is a case of "discovering" something that is already known and then expressing shock. Children need summer sunlight (without burning) and in winter they need sufficient vitamin D supplementation to maintain their summer levels. Believe me; 400 IU does not cut it.

Check with you doctor, and be sure your children have optimal levels of vitamin D, which will probably require at least 1,000 IU daily.


[1] http://www.eurekalert.org/pub_releases/2008-12/jdc-jrf121508.php
[2] Hypponen, E. et al. Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study. Lancet 2001;358:1500-03.

I told you so! A new study shows that vitamin D is critically important to prevent breast cancer.

There was an uproar recently about a study indicating that vitamin D supplementation had no affect on breast cancer risk.[1] The press picked it up and regurgitated it ad nauseam as if were the end-all-be all of scientific studies. I told you then that it was bad research because it used a miniscule quantity of vitamin D—400 IU per day—rather like trying to attack an elephant with a bb gun. In fact, a 400 IU daily supplementation for seven weeks has been shown to lead to reduced vitamin D levels in winter, whereas tanning bed exposure raises vitamin levels by 150% in the same time period.[2] It should be no surprise that a vitamin D supplement that is so tiny that it leads to deficiency would not help women to prevent breast cancer.

Now we have a new study from Germany showing that women with the highest vitamin D levels have a 55% reduced risk of breast cancer compared to those with the lowest levels.[3] Another study showed that three years of supplementation with calcium and vitamin D correlated to a reduced risk of all cancers in women by up to 77%.[4] However, the supplementation was 1,100 IU per day, not 400.

What can I say? I told you so.


[1] Chlebowski R, et al. Calcium Plus Vitamin D Supplementation and the Risk of Breast Cancer. JNCI Published online 11-11- 2008.
[2] Holick, M. et al. Boston University. "Effects Of Vitamin D And Skin's Physiology Examined." Science Daily 21 February 2008 .
[3] Abbas, S. et al. Plasma 25-hydroxyvitamin D and premenopausal breast cancer risk in a German case-control study. Int J Cancer 2009;124:250-5.
[4] Lappe, J. et al. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 2007;85:1586–91.

Vitamin D, Flu and the Immune System: Part 2

We now have the answer to preventing the next flu pandemic. This is the second part of the blog on flu. See the first for the background information.

Dr. John Cannell and his colleagues wrote a remarkable paper[1] showing that cold and flu outbreaks are almost completely seasonal. In the northern hemisphere, they occur in December through March. In the southern hemisphere, outbreaks occur June through September—almost exclusively in winter in both hemispheres. The outbreaks of flu and colds in each case occur in times of lowest UVB light and therefore the time of least vitamin D production. It follows then, that essential cathelicidin production is also extremely low during winter, which dramatically dampens the immune response. It would stand to reason, if the theory is correct, that flu and cold outbreaks would occur mainly in winter in both hemispheres. It also stands to reason that increasing vitamin D blood levels by supplementation would be able to reduce the incidence of colds and fly in winter. This is exactly the case.

Shortly after this paper’s publication, other researchers reported results of a three-year study of African-American women.[2] One group was given a placebo and another group received 800 IU per day for two years and 2,000 IU during the third year. The placebo group experienced three times as many cold and flu cases as those who received 800 IU. The 2,000-IU group had only one cold or flu case the entire year, and none in winter. The placebo group had 24 cases in winter—that is a 24:0 ratio!

These findings are especially important because flu shots are not very effective. A review in the British Medical Journal came to the following conclusion: “Evidence from systematic reviews shows that inactivated vaccines [flu shots] have little or no affect on the effects measured.”[3] Perhaps flu shots do save some lives, but there is little doubt that vitamin D does a profoundly better job. Considering that daily supplementation with 2,000 IU per day of vitamin D can cost as little as $10.00 per year, a tremendous financial burden could be lifted from the health-care system and from the budget of elderly persons!

Approximately 36,000 people die yearly from flu in the USA, and it is estimated that a pandemic similar to the one in 1918 could kill a billion people worldwide. It simply does not need to happen. The solution: maintain higher vitamin D levels. This can be done during winter by vitamin D3 supplementation of at least 2,000 IU, and as much as 5,000 IU per day in the absence of UVB exposure. Do not use vitamin D2; it is not nearly as effective.

The flu season is upon us. This year, work to maintain adequate vitamin D levels and kiss the flu goodbye!

[1] Cannell, J. et al. Epidemic Influenza and vitamin D. Epidemiol Infect 2006;134:1129-40.
[2] Aloia, J. et al. Colds and Flu. Letter to the editor. Epidemiol Infect Jan 15, 2007.
[3] Jefferson, T. et al. Influenza vaccination: policy versus evidence. BMJ. 2006;333::912-15.

Vitamin D, the Immune System and the Yearly Outbreaks of Flu

This year, kiss the flu goodbye!

Vitamin D boosts the immune system and enhances the body’s ability to kill bacteria or viruses—intercellular invaders—that make their way into body cells. When a mechanism known as a toll-like receptor (TLR) recognizes the invaders, it causes direct anti-germ activity by stimulating the action of peptide proteins that bind to and kill viruses, bacteria and fungi.[i] [ii] [iii]
The peptides are called cathelicidins, and they do their work by breaking down the cell walls of viruses and bacteria.[iv] The gene that turns on cathelicidin is a direct target of vitamin D. Therefore, it is vitamin D that triggers the action of cathelicidins against all of these “invaders, [v] including the viruses that cause flu and colds.

It is important to understand that ultraviolet B light (UVB) is the wave length of sunlight that, when it contacts the skin, stimulates the skin to produce vitamin D. The skin does not produce any vitamin D unless UVB is available. UVB, plentiful in summer sunshine, is filtered out in winter at high latitudes because of the sun’s position in the southern sky (northern sky in the southern hemisphere). This is called “vitamin D winter.” Blood vitamin D levels, therefore, become very low in winter unless some other method is used to keep them at desirable levels. So what does all this have to do with flu and colds? I will post the answer in my next blog.

[i] Zhang, L. et al. Contribution of Human -Defensin 1, 2, and 3 to the Anti-HIV-1 Activity of CD8 Antiviral Factor. Science 2002;298:995-1,000.
[ii] Wang, T. et al. Cutting edge: 1,25-dihydroxyvitamin D3 is a direct inducer of antimicrobial peptide gene expression. J Immunol 2004;173:2909-12.
[iii] Herr, C. et al. The role of cathelicidin and defensins in pulmonary and inflammatory diseases. Expert Opin Biol Ther 2007;7:1449-61.
[iv] Liu, P. et al. Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response. Science 2006;311:1770-73.
[v] Gombart, A. et al. Human cathelicidin antimicrobial peptide (CAMP) gene is a direct target of the vitamin D receptor and is up-regulated in myeloid cells by 1,25-dihydroxyvitamin D3. FASEB J 2005;19:1067-77.

Sunlight, vitamin D, flu and schizophrenia.

This is my third post concerning the relationship between vitamin D deficiency and brain disorders. Now I make the case that a major cause of schizophrenia is lack of sunlight or other source of vitamin D.

People born in seasons of little sunlight have higher schizophrenia risk.[1] Schizophrenia is also more common in dark-skinned migrants to cold climates, and increased rates of schizophrenia are observed in urban compared to rural settings.[2] Migrants to colder climates are 4.6 times more likely to develop schizophrenia than are natives.[3] Another indication, proposed by Dr. William Grant,[4] is the correlation of influenza during women’s pregnancies to increased schizophrenia in their children. Indeed, an investigation in Denmark demonstrated that flu during pregnancy predicted an 820% increased incidence of schizophrenia in children.[5] That result could be due to brain damage resulting from the high fevers common to flu; it has been shown that there is a close relationship between fever in the pregnant mother and the risk of later schizophrenia in her children.[6]

But what does this have to do with vitamin D or sunlight? Earlier I established that in summer, when vitamin D production is high, flu is nearly non-existent and that vitamin D supplementation in sufficiently high doses reduces the risk of flu to almost zero in the winter. Vitamin D stimulates the production of cathelicidins in the immune system. Cathelicidins destroy the cell walls of viruses, thereby keeping the flu at bay. Therefore, vitamin D, by preventing flu, may help reduce schizophrenia risk provoked by fevers during pregnancy. Vitamin D, then, has a direct affect on the brain that reduces the risk of schizophrenia and an indirect effect by reducing the risk of flu. A further dramatic indication is that infant boys who are not supplemented with vitamin D are 12 times more likely to develop schizophrenia in later life compared to those who receive supplementation.[7]

Vitamin D receptors are prevalent throughout the brain. Those receptors are there for a purpose: proper brain development and function. If we allow deficiency in our children, we do so at their peril.


[1]McGrath, J. et al. Long-term trends in sunshine duration and its association with schizophrenia birth rates and age at first registration—data from Australia and the Netherlands. Schizophr Res 2002;54:199-212.
2 McGrath, J. et al. Hypothesis: Is low prenatal vitamin D a risk-modifying factor for schizophrenia? Schizophr Res 1999;40:173-77.
[3] McGrath, J. et al. A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology. BMC Med 2004;2:13-35.
4Grant, W. Personal communication with author, June, 2006.
5 Byrne, M. Obstetric conditions and risk of first admission with schizophrenia: a Danish national register based study. Schizophr Res 2007;97:51-59.
6Edwards MJ. Hyperthermia in utero due to maternal influenza is an environmental risk factor for schizophrenia. Congenit Anom (Kyoto);2007;47:84-9.
7 McGrath J, et al. Vitamin D supplementation during the first year of life and risk of schizophrenia: a Finnish birth cohort study. Schizophr Res. 2004;67:237-45.

African Americans and Vitamin D, Part 4: Sickle Cell Disease

Sickle cell disease is a disease of black people. It causes a usually fatal anemia and is marked by sickle-shaped red blood cells. It is also characterized by joint pain, fever, leg ulcers, and jaundice. It has recently been reported that vitamin D deficiency is five times more common among blacks who have sickle cell disease.[1] [2] Whether the disease, thought to be totally genetic, could be prevented by maintaining vitamin D at optimal levels is unknown.

We do know that vitamin D treatment of sickle cell patients increases bone density,[3] and it is likely that raising vitamin D to optimal levels would reduce the high risk of degenerative diseases that are found in all African Americans with low levels (see my previous posts on the subject). In my opinion, it is imperative to act immediately to assure that African Americans and all Americans optimize their blood levels of vitamin D. The research is in; the conclusion that vitamin D deficiency is causing a health crisis is incontrovertible. The time to act is now!


[1] Rovner, A. et al. High risk of vitamin D deficiency in children with sickle cell disease. J Am Diet Assoc. 2008;108:1512-6.
[2] Buison, A. et al. Low vitamin D status in children with sickle cell disease. J Pediatr. 2004;145:622-7.
[3] Adewoye, A. Sickle cell bone disease: response to vitamin D and calcium. Am J Hematol. 2008;83:271-4.

African Americans, Part 3: Vitamin D and Rickets

Rickets, a deforming, crippling bone disease of infants and young children, is a well-established vitamin D-deficiency disease. Children with adequate levels of vitamin D simply don’t get rickets. Nevertheless, rickets has made a comeback, and between 1990 and 2000 increased by 400% among black children.[1] The reasons:

1. The Powers of Darkness (the POD or sunscare industry) insist that all children be “protected” from sunlight, meaning that the most natural method of vitamin D production—sunlight exposure—is denied to infants, young children and expectant mothers—mothers who must produce sufficient vitamin D to meet their own needs and the needs of both their unborn babies. Sunscreen “protection” reduces vitamin D synthesis in the skin by 99.5%[2]. This is a disaster for black children and expectant mothers who are already vitamin D-deficient.

2. The food that is fortified with vitamin D for mass consumption is milk; however, much of the black population is intolerant to lactose (milk sugar) and cannot drink milk. This intolerance has been known of for decades, and yet the “authorities” continue to fortify a food not conducive to health in black Americans. Was this done purposely? I certainly hope not. It is probably incompetence rather than conspiracy, but it seems too stupid.

3. Black skin can take 6 times longer than white skin to make a given amount of vitamin D.[3] Therefore, to suggest that African Americans avoid the sunlight is criminal. Yet, despite protestations to the contrary by the POD, we have become a nation of indoor dwellers—perhaps the only true cave men that ever existed. This assures that blacks, who already have a very difficult time making vitamin D, are further denied this life-giving hormone.
When these factors combine, they produce the vitamin D deficiencies that lead to rickets—a 100% preventable disease. The POD are responsible for the resurgence of this disease.

Will the Powers of Darkness be overcome by light and truth or will they continue to spread the message that results in death and destruction?

[1] Schwartz, R. Science News Aug 17, 2000.
[2] Matsuoka, L. et al. Sunscreens suppress cutaneous vitamin D3 synthesis. Journal of Clinical Endocrinology & Metabolism 1987; 64:1165-68.
[3] Harris, S. et al. Seasonal changes in plasma 25-hydroxyvitamin D concentrations of young American black and white women. Am J Clin Nutr 1998;67:1232-36.

Sunlight, vitamin D and African Americans, Part 2

In my previous post, I discussed reasons to believe that the generally poor health of African Americans is due in large part to vitamin deficiency. Here are more reasons to believe that the need for vitamin D is critical among this population.

1. Heart disease is twice as prevalent among black men as white men.[1] Although part of the discrepancy may be due to more smoking among black men, it is probable that a significant part is due to vitamin D deficiency. Low sun exposure and low vitamin D levels correlate to increased inflammation, higher cholesterol and hypertension, all risk factors for heart disease.

2. Heart failure is also much more common among blacks[2]—not surprising since we know the efficacy of vitamin D in preventing heart failure.

Now let’s discuss what is perhaps the most important study for African Americans. It is often argued that the excessive rates of cancer, diabetes, hypertension, etc. among African Americans are due to lack of access to health care. If that were the case, black physicians would have approximately the same lower rates of disease as their white counterparts, since black physicians obviously have high access to health care. However, research shows that even black physicians have a much higher incidence of cancer than their white counterparts.[3] But when black physicians have habits that provide higher vitamin D levels, they have approximately the same cancer rates as white physicians. Had the rates of heart disease, diabetes, hypertension and other diseases also been studied, along with measurements of serum vitamin D levels, I believe the pattern would have been even more clearly established.

Since African Americans have only 50-75% of the serum levels of vitamin D as whites,5 part—perhaps a large part—of the discrepancy between the health of the races could be rectified by nothing more than vitamin D supplementation of about 5,000 IU daily. That is very good news indeed!

[1] USA Department of Health and Human Services 1998. Tobacco Use Among USA Racial/Ethnic Minority Groups — African Americans, American Indians and Alaska Natives, Asian Americans and Pacific Islanders, and Hispanics: A Report of the Surgeon General. Atlanta: USA Department of Health and Human Services, Centers for Disease Control and Prevention.
[2] American Heart Association. Heart and stroke statistics – 2004 update.
[3] Giovannucci, E. et al. Cancer Incidence and Mortality and Vitamin D in Black and White Male Health Professionals: Cancer Epidemiol Biomarkers Prev 2006;15:2467–72.

Critical vitamin D deficiency and critically poor health among African Americans: Part 1

Why do African Americans suffer more from heart disease, cancer, hypertension, diabetes and other degenerative diseases than white Americans? One reason is that vitamin D deficiency is far more common in blacks.

In my book, I documented the relationship of vitamin D deficiency to dramatically increased risk of diabetes, cancer, heart disease, diabetes, hypertension and numerous other diseases and conditions--105 in all. If dark-skinned Americans are more likely to be deficient, it stands to reason that they would be more likely to succumb to those diseases.
Here are some interesting facts that relate vitamin D deficiency to poor health in black Americans:

1. When USA white and black women are compared for vitamin D levels, black women are ten times more likely to be vitamin D deficient.[1]

2. In patients in Minneapolis, Minnesota who were being treated for chronic pain, 100% of African Americans, along with Native Americans, East Africans and Hispanics were vitamin D deficient.[2]

3. Vitamin D is known to be a potent inhibitor of tuberculosis. African Americans have lower resistance to tuberculosis, lower levels of D and lower ability to produce cathelicidin, a natural internal bactericide.[3]

4. A 37-year-old disabled Black woman with myopathy (a muscle disease) and severe vitamin D deficiency was able to leave her wheelchair and function normally after six weeks of vitamin D therapy.[4]

5. Vitamin D deficiency leads to increased death from the major internal cancers, and a disproportionate number of those cancer deaths occur in African Americans.[5] Dr. William Grant, in summarizing the findings of his study on African Americans and cancer, wrote that “Solar UVB was found significantly inversely correlated with mortality rates for breast, colon, esophageal, gastric and rectal cancers for black Americans.” Other research in 2008 corroborated his findings, showing that in the Southeast USA, vitamin D deficiency is about four times more common in African Americans as whites, suggesting that the greater cancer risks among African Americans is due to that deficiency.[6]

Shortly I will post another blog citing research that further establishes vitamin D deficiency as a likely culprit in the poor health of dark-skinned Americans.

[1] Nesby-O’Dell, S. et al. Hypovitaminosis D prevalence and determinants among African American and white women of reproductive age: third National Health and Nutrition Examination Survey, 1988-1994. Am J Clin Nutr 2002;76:187-92.
[2] Plotnikoff G. et al. Prevalence of severe hypovitaminosis D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc. 2003;78:1463-70.
[3] Liu, P. et al. Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response. Science. 2006;311:1770-73.
[4] Prabhala, A. et al. Severe myopathy associated with vitamin D deficiency in western New York. Arch Intern Med 2000;160:1199-1203.
[5] Grant, W. Lower vitamin-D production from solar ultraviolet-B irradiance may explain some differences in cancer survival rates. JNMA 2006;98:364
[6] Egan, K. et al. Vitamin D insufficiency among African Americans in the southeastern United States: implications for cancer disparities (United States). Cancer Causes Control 2008;19:527-35.