In addition to the current epidemic of vitamin D deficiency, say another epidemic—an epidemic of autism—was upon our children? What if the autism epidemic began at the same time the epidemic of vitamin D deficiency began? What if both epidemics had worsened in unison? What if one theory explained all the unexplained facts about autism? What if both epidemics had the same root cause: sun avoidance? What if both were iatrogenic, that is, medical advice to avoid the sun had caused both epidemics? Be warned, what follows is not light reading—autism is not a light disease.

Does The Vitamin D Theory Best Autism?

The theory that vitamin D deficiency, during pregnancy or childhood, causes autism is just a theory. However, the theory has a plausible mechanism of action, explains all the unexplained facts about autism, subsumes several other theories, implies simple prevention, and is easily disprovable—all components of a useful theory. A genetic lesion (abnormality) in some component of the vitamin D system—a lesion vitamin D’s unique pharmacology could overcome—would explain why monozygotic (identical) twins are highly affected while fraternal twins are not. Varying brain levels of activated vitamin D during later life would explain why some identical twins get severe disease while others are barely affected. Falling vitamin D levels over the last 20 years due to sun-avoidance explain autism’s rapid increase in incidence during that same time. The very different effects estrogen and testosterone have on vitamin D metabolism may explain why boys are much more likely to get it than girls are. Lower vitamin D levels in blacks may explain their higher rates of autism. The vitamin D theory has tenable explanations for all the epidemiological features of autism.

What’s The Risk of Going in The Sun?

The window of opportunity to affect brain development is limited. Time is of the essence if the vitamin D theory of autism is correct. Ask yourself, what is the risk of taking your autistic child outside to play in the sun? What’s the risk of pregnant women sunbathing for a few minutes every day? Children always played in the sun before the epidemic of autism; your pregnant grandmother spent time in the sun as well. Physicians considered that sunshine was healthy before the sun-scare, that is, before autism became an epidemic.

Since autism was first added to the psychiatric literature fifty years ago, there have been numerous studies and theories about its cause. Researchers still have not reached agreement regarding its specific causes. First, it must be recognized that autism is a set of a wide variety of symptoms and may have many causes. This concept is not unusual in medicine. For instance, the set of symptoms that we perceive of as a “cold” can be caused by literally hundreds of different viruses, bacteria, and even our own immune system. Autism is, undoubtedly, a biologically-based disorder. In the past, some researchers had suggested that autism was the result of poor attachment skills on the part of the mother. This belief has caused a great deal of unnecessary pain and guilt on the part of the parents of autistic children, when in fact, the inability of the individual with autism to interact appropriately is one of the key symptoms of this developmental disorder.

In support of a biological theory of autism, several known neurological disorders are associated with autistic features. Autism is one of the symptoms of these disorders. These conditions include tuberous sclerosis (an inherited disorder), the fragile X syndrome, cerebral dysgenesis (abnormal development of the brain), Rett syndrome, and some of the inborn errors of metabolism (biochemical defects). Autism, in short, seems to be the end result or “final common pathway” of numerous disorders that affect brain development. In general, however, when clinicians make the diagnosis of autism, they are excluding the known causes of autistic behaviors. However, as the knowledge of conditions that cause autism advances, fewer and fewer cases will be thought of as being “pure” autism and more individuals will be identified as having autism due to specific causes.

There is a strong association between autism and seizures. This association works in two ways: First, many patients (20% to 30%) with autism develop seizures. Second, patients with seizures, which are probably due to other causes, may develop autistic-like behaviors. One special and often misunderstood association between autism and seizures is the Landau-Kleffner Syndrome. This syndrome is also known as acquired epileptic aphasia. Some children with epilepsy develop a sudden loss of language skills–especially receptive language (the ability to understand). Many often also develop the symptoms of autism.

These children often, but not always, have a characteristic pattern of electrical brain activity seen on EEG (electroencephalogram) during deep sleep called electrographic status epilepticus during sleep (ESES). The usual age of onset of language loss or regression is around four years of age, which makes the Landau-Kleffner syndrome distinguishable from autism on these grounds, in that autism usually is first exhibited in younger children. However, in recent years, some children (very, very few) who did not exhibit overt (observable) seizures were found to have Landau-Kleffner syndrome.

The importance of these findings is that, although rare, the Landau-Kleffner syndrome can resolve spontaneously and in some cases can be treatable with prednisone, a steroid medication related to cortisone. This association between the Landau-Kleffner syndrome and autism has led many clinicians and families to search for the typical EEG pattern (ESES) in autistic individuals. This unusual EEG pattern is seen only in deep sleep, which usually requires prolonged recordings of up to 12 hours. Many, many autistic children and adults will display some abnormalities on their sleep EEG, but probably very few have true Landau-Kleffner syndrome that will respond to treatment.

It must also be noted that prednisone, in the very high doses used to treat Landau-Kleffner syndrome, almost invariably produces side effects, which may include weight gain, high blood pressure, diabetes, growth failure, stomach ulcers, irritability, destruction of the hip joint, and susceptibility to infectious disease (suppressed immune system). While most of these side effects are reversible, some of the complications of high dose prednisone therapy can be irreversible and even fatal.

Other treatments ranging from common anticonvulsant therapy to surgery have been proposed and are being tried for Landau-Kleffner syndrome. It is difficult to evaluate the true effects of any treatment for Landau-Kleffner syndrome due to the high rate of spontaneous resolution of symptoms (remission).