The Role that Vitamin D and the Environment Have in Autism

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The Role that Vitamin D and the Environment Have in Autism
By AnnElise Hatjakes, M.A. Contributing Writer Kirkman Group, Inc.
Vitamin D deficiency has long been associated with increased risk for osteoporosis and rickets. However, according to research done by Dr. John Cannell, an expert in the field of vitamin D, maternal vitamin D deficiency may also be tied to neurodevelopmental disorders like autism. Researcher Rebecca Schmidt, Ph.D., is leading a new study that will retrospectively examine the role of nutrients in fetal development. Both of these studies indicate scientists’ growing interest in the relationship between nutrients (like vitamin D and folate) and autism. Dr. Schmidt, an assistant professor at the Department of Public Health Sciences and UC Davis MIND Institute, studies how autism is related to the way genes interact with environmental factors to increase autism risk. In California, blood spots taken from newborns are archived, which provides researchers with the opportunity to study the levels of folate and other nutrients. Because these blood spots are taken before the child is diagnosed with any disorder, there is a lower risk of recall bias. Dr. Schmidt will study the composition of 1,000 blood spots and determine whether or not those newborns later developed autism. She will then identify if there is a link between various nutrient levels and autism. “Some animal studies have shown that vitamin D deficiency might be tied to language development,” Dr. Schmidt said in an interview.1 She added that these studies have not yet been replicated in humans. Dr. Schmidt is also working on a prospective study that will involve doing measurements of women’s nutrient levels throughout their pregnancies and then determining whether or not their children develop disorders later in life. With regard to folic acid, Dr. Schmidt said, “Our findings were replicated in a large-scale study in Norway of 85,000 kids. They found the same exact trend. Women who took folic acid really early in their pregnancy had a 40 percent reduced risk for autism. That’s because folic acid helps with methylation, which plays a big role in gene expression and development.” In addition to his finding that maternal vitamin D deficiency was linked to increased autism risk, Dr. Cannell explained in one paper that vitamin D may help ameliorate some symptoms associated with autism. “A placebo controlled three-month study of 20 autistic children found multi-vitamins with even low doses of vitamin D (150 units or 3.75 mcg) significantly improved sleep and gastrointestinal problems.”2
One function of vitamin D is increasing cellular levels of glutathione, which Dr. Cannell suggests may explain the “purported link between heavy metals, oxidative stress, and autism. For example, calcitriol attenuates iron-induced and zinc-induced oxidative injuries in rats’ brains.”2 Environmental Factors and Autism Recent studies suggest that various environmental factors such as exposure to environmental pollutants and toxins may play a role in the development of autism as well. “We know from brain imaging studies and autopsy studies how brains differ in people with autism,” Dr. Schmidt said. “These differences seem to occur during the [fetal] brain’s development.” She added that the correlation between air pollution exposure during pregnancy and autism risk has been replicated in many studies. “Fever during pregnancy and even metabolic conditions like high blood pressure, obesity, and diabetes affect the child’s development,” Dr. Schmidt said. However, the latter correlation has not yet been replicated in a large-scale study. Pregnancy and Nutrition “Nutrition is making a comeback as far as being seen as an important factor [during pregnancy],” Dr. Schmidt said. She recommended that women take folic acid if they plan to become pregnant and take a prenatal vitamin once they become pregnant. “The recommendations that are out there are important to follow,” Dr. Schmidt said. “There is a short window of time early in the pregnancy that’s impo rtant to catch as far as paying attention to nutrition.” Dr. Schmidt explained that short intervals between pregnancies could lead to nutrient depletion. “Something to keep in mind is epigenetics,” Dr. Schmidt said. “Autism has genetic links. For example, twin studies show that when one has the genome with autistic indicators, the other is likely to also have it. A mother’s environment when the child is developing plays just as large a role. It seems to be 40 percent genes, 60 percent environment. The environment is the factor that we can change.”
Schmidt, R. (2014, January 24). Telephone interview.
Cannell, M.D., J. J. (2007, August). Autism and vitamin D. Medical Hypotheses, 70.