Autism: A New Theory

BY JOHN J. CANNELL, MD It’s time to look at autism a new way – with a new theory.

If the CDC’s worst-case scenario of a 12 percent yearly increase in the incidence of autism proves to be true, we will be in serious trouble in terms of caring for these individuals.

Over the past 20 years, scientists have assured us that effective prevention and treatment of autism are just a matter of time. However, as time passes, the epidemic shows no signs of abating. A recent Forbes article reports that, in the next decade, half a million US children with autism will become adults, ballooning the number of autistic adults by 50 percent.1 The same article reports that most young autistic adults spend their days in adult daycare; only 18 percent are employed, and even fewer live independently.

If the Centers for Disease Control and Prevention’s (CDC’s) worst-case scenario of a 12 percent yearly increase in the incidence of autism proves to be true, we will be in serious trouble in terms of caring for these individuals.2 It’s time to look at autism a new way – with a new theory.


In October 2007, I published a paper in the British journal Medical Hypotheses that proposed a completely new explanation for autism.3 I argued that autism was not caused by a toxin, virus, vaccine, solvent, or classic genetic mutation. Instead, I proposed that autism is the result of:

a. a predisposing genetic abnormality in the way the body processes vitamin D,

b. a noxious triggering event, and

c. a dramatic and very recent epidemic of vitamin D deficiency.

This combination injures the built-in repair systems the human body has developed over two million years to protect against and repair cellular injuries.4

Remember, whether injuries such as small mutations pop up from background radiation, inflammation, or the products of combustion or toxins, the immune system must be able to prevent and repair the damage. I wondered
whether the immune system could have suffered a dramatic injury over the past 30 years.

In my article, I argued that the genetics of the vitamin D system (all the body’s “machinery” that goes into making
vitamin D) could explain autism. I realized that, instead of severe mutations in the vitamin D system, genetic variations in the body’s capacity to metabolize vitamin D plus vitamin D deficiency could explain autism. That
is, if you inherited only a little of the enzyme that turns vitamin D into a steroid hormone and you also weren’t getting enough vitamin D, these two problems together would keep your brain from getting the activated vitamin D it needs to develop.

On the other hand, if you inherited a lot of the enzyme that activates vitamin D or many vitamin D receptors (that increase uptake of vitamin D), your brain would be able to get most of the vitamin D it needs.

This, I believe, is why autism has been passed down for ages from parent to child without harm – but the disorder’s incidence rate has exploded only since the emergence of the vitamin D deficiency epidemic.

More important, my 2007 paper explored autism from the viewpoint that the best theory is the one that can explain
the most facts in the simplest manner; that is, one theory explaining eight facts is much better than eight different theories explaining eight different facts.3 Three years later, I updated my vitamin D theory of autism in the 90-year-old journal Acta Paediatrica.5 Furthermore, I now conclude that the genetic injuries in autism – the small, new point mutations – are the effects and not the causes of autism. Vitamin D is in charge of increasing the number of proteins made in the body to repair its own DNA. Thus, vitamin D deficiency prevents repair of these ongoing genetic injuries.


Our body’s natural ability to defend itself against assaults has been stripped of its effectiveness by perhaps the worst advice physicians have ever given: stay out of the sun. That well-meaning advice should have been followed by a caveat to take extra vitamin D to make up for what the sun no longer makes in your skin, or to expose your skin to the sun for 15 minutes per day.

One of the world’s leading researchers on vitamin D, Michael Holick of Boston University, writing in The New England Journal of Medicine, contends that this sun avoidance advice has contributed heavily to what he now calls the vitamin D deficiency epidemic, which has greatly impaired our immune systems, or our ability to fight off disease.6


The best scientific theory is one that can explain the most facts in the simplest manner. Let’s take a quick look at six facts about autism and the six different theories of the scientists who discovered the facts. To quote Sir Isaac Newton, “We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Therefore, to the same natural effects we must, so far as possible, assign the same causes.”10

Fact 1: Autism has increased dramatically 

Most experts now agree that autism has risen alarmingly over the past 30 years. The scientists believing this fact thought that some unidentified environmental agent introduced during this time (such as a new vaccine) was causing the epidemic. Although most scientists believe the vaccination theory incorrect, many parents still believe it, especially those who watched their normal toddlers deteriorate at 12–18 months—about the time they received their vaccinations.

Certainly, the number of vaccinations our children receive has increased dramatically during the past 30 years. So, as our first example, we have one fact (a rapid increase in cases of autism) and one theory (vaccinations) to explain it.

Fact 2: Autism is more common in polluted areas

Several studies have shown that autism is more common in areas with polluted air, due to the toxic effect of pollutants on developing fetal brains.11,12 This theory makes sense because a number of toxins can damage genes. According to the researchers, pregnant women and young children living in polluted air have more toxins in their brains. The theory of toxins in air pollution explains Fact 2. Notice that we have two facts and two entirely different theories.

Fact 3: Autism is more common in cloudy and rainy areas

According to research by Michael Waldman and colleagues at Cornell University, the greater incidence of autism in areas with more clouds and rain, where children are more likely to take part in indoor activities, is due to the increased use of electronic devices in rainy and cloudy areas and the effect these devices have on the brains of developing children.13 Certainly, these devices have proliferated over the past 30 years, so perhaps they are emitting radiation that damages fetal and young children’s brains, causing autism.

Now we have three facts and three entirely different theories. So do we stop vaccinating our children, clean our air, or throw away our cell phones?

Fact 4: Autistic boys have thin bones

The cortex, or outer covering, of bones of autistic boys is thinner than in the bones of normal children, which some
researchers say is due to the eccentric diets of many autistic children.14 Certainly, children with autism often have unusual diets, especially those with no milk products, so a lack of calcium could certainly explain this finding. However, some unidentified toxin may be damaging both bones and brains.
Four facts, four theories.

Fact 5: Autism is more common in wealthy, educated white families

The incidence of autism is higher among better-educated and richer white families15 than it is among poor, less-educated white families. According to some studies, this is because better-educated and richer parents seek treatment for their children more often.

The finding that autism is more common in families with higher incomes and better educations is one of the most unusual and hotly debated issues about autism. Other than a statistical fluke, what could explain such an unusual fact?16

Fact 6: Autism is more common in dark-skinned people

Some, but not all, studies show that autism is more common in blacks than in whites.17–22 However, some scientists believe those findings are due to underdetection among the poor and failure to correct for socioeconomic status. For example, Bruce Ames, a member of the National Academy of Science, reports that CDC data show that the prevalence of autism among wealthy black children is twice as high as it is for wealthy white children.23

Some experts cite the same reasons most diseases are more common in blacks than in whites: poverty and poor prenatal care. Certainly, heart disease, most cancers, pneumonia, hypertension, diabetes, and autoimmune diseases are more common among blacks than whites. So why not autism? A CDC study found that black children in Atlanta were almost twice as likely to have autism—and more severe autism—than white children.16

There is no name in the Somali language for autism, but in Minnesota, home to many dark-skinned Somali immigrants, Somalis call autism the “Minnesota disease.” Somalis in Sweden call it the “Swedish disease.”

So we have our sixth fact and our sixth different explanation: autism is more common among dark-skinned people, perhaps due to poor prenatal care.


Scientists explain the six different facts outlined above using six entirely different but completely tenable theories. Can one theory alone explain all six of these facts? If so, such a theory is the best theory because it is the most prudent, economical, reasonable, and encompassing.

Here’s the theory: Autism is caused by vitamin D deficiency during pregnancy or early childhood. Let’s see if it can explain these six seemingly unconnected facts.

Fact 1: Autism has increased dramatically

The rapid increase in the incidence of autism since the late 1980s coincides almost perfectly with the timing of the
“sun scare,” with the medical profession advising people to protect themselves from skin cancer by staying out of the sun or using sunscreen, which also blocks vitamin D absorption.24 (Ultraviolet light in sunshine is now listed by the US government as a toxin.25)

Although we have no studies that show changes in vitamin D levels over the past 30 years, the average vitamin D level in the United States in 1988 was 30 ng/mL; by 2001, it was only 24 ng/mL.26 Likewise, the prevalence of extremely low vitamin D levels (less than 10 ng/mL) tripled during the same period. In Denmark, where they keep better records on vitamin D, vitamin D levels have fallen even more dramatically. Average vitamin D levels decreased from 25 ng/mL in 1994 to 20 ng/mL in 2001 and to 17 ng/mL in 2008.27,28

Could the vitamin D deficiency epidemic explain the epidemic of autism?

Fact 2: Autism is more common in polluted areas

This fact is explained by a well-conducted study that showed that air pollution reduces the amount of vitamin D–producing ultraviolet B (UVB) radiation from sunlight penetrating the atmosphere, lowering vitamin D absorption in pregnant women and thus lowering their infants’ vitamin D levels.29 However, some UVB still gets
through polluted air, so the rate of autism should be only slightly increased in polluted areas – which is the case.

Fact 3: Autism is more common in cloudy and rainy areas

Cloudy and rainy areas have a higher prevalence of autism. Those same clouds and rain greatly impair penetration of vitamin D–producing UVB light, lowering vitamin D production. People who live in cloudy and rainy areas have lower vitamin D levels than people who live in sunny areas due to clouds impairing vitamin D production in the skin. Also, people who live in rainy areas are more likely to spend more time inside, further lowering their vitamin D levels.

Fact 4: Autistic boys have thin bones

Simply put, vitamin D deficiency during pregnancy or early childhood results in thin bones – and lays the environmental groundwork for autism.30

Fact 5: Autism is more common in wealthy, educated white families

This fact (which does not apply to nearly any other disease) is explained by studies that show that wealthy, educated parents are more likely to practice sun avoidance and apply sunscreen than are low-income, less-educated parents. They are also less likely to allow unprotected sun exposure for young children31 and pregnant women.32 This situation results in lower vitamin D levels during crucial periods of brain development and, potentially, more autism.

Fact 6: Autism is more common in dark-skinned people

Although controversial and not supported by all studies,33 this fact is also explained by the vitamin D theory.  Melanin is a skin-darkening pigment that also acts as an effective sunscreen. As a result, people with a lot of melanin in their skin have low vitamin D levels. In fact, many black women of childbearing age have virtually no detectable vitamin D in their blood, meaning their babies develop in an extremely vitamin D–poor environment.34

So our one test theory explains all six facts. Few theories can explain six facts about any disease without assuming some beliefs to be true. A principle known as Occam’s razor generally recommends choosing from competing possible explanations the theory that makes the fewest assumptions (in other words, the one based on facts rather than beliefs that may or may not be true). So far, we have not had to make any new assumptions for the vitamin
D theory of autism.•

Excerpted from Dr. Cannell’s book, Autism Causes, Prevention and Treatment: Vitamin D Deficiency and the Explosive Rise of Autism Spectrum Disorder

John J. Cannell, MD, Phi Beta Kappa, activist, researcher, and founder of the Vitamin D Council, is an internationally recognized practitioner in the field of autism causes, treatment, and prevention. Routinely quoted in academic and research circles, Dr. Cannell maintains a private practice in San Louis Obispo working with newly diagnosed autistic children and their parents. In addition, he focuses extensive effort on the poorly understood effects of widespread chronic Vitamin D deficiency in the human body and its relationship to the accelerating rise of autism throughout the industrialized world.



1 Walton AG. Living Life with Autism: Has Anything Really Changed? Forbes. Nov 30, 2011.
2 Autism and Developmental Disabilities Monitoring Network Surveillance Year 2008 Principal Investigators; Centers for Disease Control and Prevention. Prevalence of autism spectrum disorders—Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2008. MMWR Surveill Summ. 2012;30;61(3):1-19.
3 Cannell JJ. Autism and vitamin D. Med Hypotheses. 2008;70(4):750-759. Epub 2007 Oct 24.
4 O’Roak BJ, Vives L, Girirajan S, Karakoc E, Krumm N, Coe BP, et al. Sporadic autism exomes reveal a highly interconnected protein network of de novo mutations. Nature. 2012;485:246-250. doi:10.1038/nature10989. [Epub ahead of print]
5 Cannell JJ. On the aetiology of autism. Acta Paediatr. 2010;99(8):1128-1130. Epub 2010 May 19.
6 Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266-81. Review.
7 Council on Physical Therapy. Regulations to govern advertising of ultraviolet generators to the medical profession only. JAMA. 1925;98:400.
8 Wright A. Immunity. Encyclopedia Britannica, 14th ed. 1929;12:117.
9 U.S. Department of Labor, Children’s Bureau, Sunlight for Babies. Folder No. 5 1931. Available at: Accessed June 8, 2014.
10 Hawking, Stephen (2003). On the Shoulders of Giants. Running Press. p. 731. ISBN 0-7624-1698-X.
11 Kalkbrenner AE, Daniels JL, Chen JC, Poole C, Emch M, Morrissey J. Perinatal exposure to hazardous air pollutants and autism spectrum disorders at age 8. Epidemiology. 2010;21(5):631-641.
12 Windham GC, Zhang L, Gunier R, Croen LA, Grether JK. Autism spectrum disorders in relation to distribution of hazardous air pollutants in the San Francisco Bay area. Environ Health Perspect 2006;114(9):1438-1444.
13 Waldman M, Nicholson S, Adilov N, Williams J. Autism prevalence and precipitation rates in California, Oregon, and Washington counties. Arch Pediatr Adolesc Med. 2008;162(11):1026-1034.
14 Hediger ML, England LJ, Molloy CA, Yu KF, Manning-Courtney P, Mills JL. Reduced bone cortical thickness in boys with autism or autism spectrum disorder. J Autism Dev Disord. 2008;38(5):848-856.
15 Durkin MS, Maenner MJ, Meaney FJ, Levy SE, DiGuiseppi C, Nicholas JS, et al. Socioeconomic inequality in the prevalence of autism spectrum disorder: evidence from a U.S. cross-sectional study. PLoS One. 2010;12;5(7):e11551.
16 Bhasin TK, Schendel D. Sociodemographic risk factors for autism in a US metropolitan area. J Autism Dev Disord 2007;37(4):667-677.
17 Croen LA, Grether JK, Hoogstrate J, Selvin S. The changing prevalence of autism in California. J Autism Dev Disord 2002;32(3):207-215.
18 Hillman RE, Kanafani N, Takahashi TN, Miles JH. Prevalence of autism in Missouri: changing trends and the effect of a comprehensive state autism project. Mo Med 2000;97(5):159-163.
19 Keen DV, Reid FD, Arnone D. Autism, ethnicity and maternal immigration. Br J Psychiatry. 2010;196(4):274-281.
20 Goodman R, Richards H. Child and adolescent psychiatric presentations of second-generation Afro-Caribbeans in Britain. Br J Psychiatry 1995;167(3):362-369.
21 Gillberg C, Schaumann H, Gillberg IC. Autism in immigrants: children born in Sweden to mothers born in Uganda. J Intellect Disabil Res 1995;39(Pt 2):141-144.
22 Dealberto MJ. Prevalence of autism according to maternal immigrant status and ethnic origin. Acta Psychiatr Scand. 2011;123(5):339-348. doi: 10.1111/j.1600-0447.2010.01662.x. Epub 2011 Jan 11.
23 Patrick RP, Ames BN. Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism. FASEB J. 2014;28(6):2398-2413. Epub 2014 Feb 20.
24 Faurschou A, Beyer DM, Schmedes A, Bogh MK, Phillipsen PA, Wulf HC. The relation between sunscreen layer thickness and vitamin D production after UVB exposure—a randomized clinical trial. Br J Dermatol. 2012;167(2):391-395. doi: 10.1111/j.1365-2133.2012.11004.x.
25 Ultraviolet (UV) Radiation, Broad Spectrum and UVA, UVB, and UVC—National Toxicology Program. 2009-01-05. Retrieved June 6, 2014.
26 Ginde AA, Liu MC, Camargo CA Jr. Demographic differences and trends of vitamin D insufficiency in the US population, 1988-2004. Arch Intern Med. 2009;169(6):626-632.
27 Skaaby T, Husemoen LL, Thuesen BH, Pisinger C, Jørgensen T, Roswall N, et al. Prospective population-based study of the association between serum 25-hydroxyvitamin-D levels and the incidence of specific types of cancer. Cancer Epidemiol Biomarkers Prev. 2014;23:1220-1229.
28 Grant WB. Why the prospective population-based study in Denmark did not find an association of 25-hydroxyvitamin D levels with cancer incidence rates, CEBP EPI-14-0530. Accepted June 2014.
29 Baïz N, Dargent-Molina P, Wark JD, Souberbielle JC, Slama R, Annesi-Maesano I; EDEN Mother-Child Cohort Study Group. Gestational exposure to urban air pollution related to a decrease in cord blood vitamin D levels. J Clin Endocrinol Metab. 2012;97(11):4087-4095.
30 Abrams SA, O’Brien KO. Calcium and bone mineral metabolism in children with chronic illnesses. Annu Rev Nutr. 2004;24:13-32.
31 Robinson JK, Rigel DS, Amonette RA. Summertime sun protection used by adults for their children. J Am Acad Dermatol 2000;42(5 Pt 1):746-753.
32 Hall HI, Jorgensen CM, McDavid K, Kraft JM, Breslow R. Protection from sun exposure in US white children ages 6 months to 11 years. Public Health Rep 2001;116(4):353-361.
33 Developmental Disabilities Monitoring Network Surveillance Year 2010 Principal Investigators; Centers for Disease Control and Prevention (CDC). Prevalence of autism spectrum disorder among children aged 8 years – Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2010. MMWR Surveill Summ. 2014;63(2):1-21.
34 Bodnar LM, Simhan HN, Powers RW, Frank MP, Cooperstein E, Roberts JM. High prevalence of vitamin D insufficiency in black and white pregnant women residing in the northern United States and their neonates. J Nutr 2007;137(2):447-452.
35 Kaplan P, Wang PP, Francke U. Williams (Williams Beuren) syndrome: a distinct neurobehavioral disorder. J Child Neurol 2001;16(3):177-190.
36 Garabédian M, Jacqz E, Guillozo H, Grimberg R, Guillot M, Gagnadoux MF, et al. Elevated plasma 1,25-dihydroxyvitamin D concentrations in infants with hypercalcemia and an elfin facies. N Engl J Med 1985;312(15):948-952.
37 Knudtzon J, Aksnes L, Akslen LA, Aarskog D. Elevated 1,25-dihydroxyvitamin D and normocalcaemia in presumed familial Williams syndrome. Clin Genet 1987;32(6):369-374.
38 Mervis CB, Klein-Tasman BP. Williams syndrome: cognition, personality, and adaptive behavior. Ment Retard Dev Disabil Res Rev 2000;6(2):148-158.

Leave a Reply