The Black Community: A Tragic Injustice
Is autism more common in dark-skinned people?
Vitamin D deficiency discriminates based on race, or more precisely, the amount of melanin (pigment) in the skin, which is an effective and ever-present sunscreen. The vitamin D theory of autism predicts that autism is more common in children born to darker-skinned mothers. Such studies are difficult as they raise sensitive social issues, although 3 of 4 recent U.S. studies found a higher incidence of autism in black children—sometimes appreciably higher. Bhasin TK, Schendel D. Sociodemographic Risk Factors for Autism in a US Metropolitan Area. J Autism Dev Disord. 2007 Apr;37(4):667–77. Croen LA, et al. The changing prevalence of autism in California. J Autism Dev Disord. 2002 Jun;32(3):207–15. Hillman RE, et al. Prevalence of autism in Missouri: changing trends and the effect of a comprehensive state autism project. Mo Med. 2000 May;97(5):159–63. Yeargin-Allsopp M, et al. Prevalence of autism in a US metropolitan area. JAMA. 2003 Jan 1;289(1):49–55.
In Europe, autism rates are higher in children of dark-skinned immigrants. Dr. Gillberg and colleagues reported that the incidence of autism in Sweden for children born to mothers who emigrated from Uganda was 15%—almost 200 times higher than the general population. Goodman R, Richards H. Child and adolescent psychiatric presentations of second-generation Afro-Caribbeans in Britain. Br J Psychiatry. 1995 Sep;167(3):362–9. Gillberg C, Schaumann H, Gillberg IC. Autism in immigrants: children born in Sweden to mothers born in Uganda. J Intellect Disabil Res. 1995 Apr;39 ( Pt 2):141–4. Newschaffer CJ, et al. The Epidemiology of Autism Spectrum Disorders (*). Annu Rev Public Health. 2007 Apr 21;28:235–258.
The Centers for Disease Control in Atlanta and others report black children have significantly higher rates of mild mental retardation than white children do and socioeconomic factors cannot explain the differences. Yeargin-Allsopp M, Drews CD, Decoufle P, Murphy CC. Mild mental retardation in black and white children in metropolitan Atlanta: a case-control study. Am J Public Health. 1995 Mar;85(3):324–8. Drews CD, Yeargin-Allsopp M, Decoufle P, Murphy CC. Variation in the influence of selected sociodemographic risk factors for mental retardation. Am J Public Health. 1995 Mar;85(3):329–34.
Several studies indicate black mothers are more likely to give birth to infants who weigh less and low birth weight is a clear risk factor for autism. Shiao SY, Andrews CM, Helmreich RJ. Maternal race/ethnicity and predictors of pregnancy and infant outcomes. Biol Res Nurs. 2005 Jul;7(1):55–66. Alexander GR, et al. Racial differences in birthweight for gestational age and infant mortality in extremely-low-risk US populations. Paediatr Perinat Epidemiol. 1999 Apr;13(2):205–17. Alexander GR, et al. US birth weight/gestational age-specific neonatal mortality: 1995–1997 rates for whites, hispanics, and blacks. Pediatrics. 2003 Jan;111(1):e61–6. Kolevzon A, Gross R, Reichenberg A. Prenatal and perinatal risk factors for autism: a review and integration of findings. Arch Pediatr Adolesc Med. 2007 Apr;161(4):326–33.
Black babies have lower Apgar scores. (Apgar tests are 10 point examinations done shortly after birth.) Low Apgar scores are associated with both poor vitamin D intake and with autism. Hegyi T, et al. The apgar score and its components in the preterm infant. Pediatrics. 1998 Jan;101(1 Pt 1):77–81. Sabour H, et al. Relationship between pregnancy outcomes and maternal vitamin D and calcium intake: A cross-sectional study. Gynecol Endocrinol. 2006 Oct;22(10):585–9. Larsson HJ, et al. Risk factors for autism: perinatal factors, parental psychiatric history, and socioeconomic status. Am J Epidemiol. 2005 May 15;161(10):916–25; discussion 926–8.
Recent studies of vitamin D deficiency during pregnancy show striking racial inequities in maternal vitamin D levels. Professor Lisa Bodnar of the University of Pittsburg and her colleagues found that only 37% of white women, but only 4% of black women, in the northern United States were vitamin D sufficient in early pregnancy. That is, 96% of pregnant black women and 63% of pregnant white women did not have adequate vitamin D blood levels. Their infants fared little better and showed the same racial inequity. 45% of the pregnant black women and only 2% of the pregnant white women were severely deficient. Prenatal vitamins, virtually all of which contain only 400 IU of vitamin D, offered little protective effect for mother or infant; 90% of the women in the study reported taking them, to little or no effect. Bodnar LM, et al. High prevalence of vitamin D insufficiency in black and white pregnant women residing in the northern United States and their neonates. J Nutr. 2007 Feb;137(2):447–52.
Unless infants take enough vitamin D after birth—either via direct supplementation or enriched formula—infant vitamin D levels are remarkably low, with black infants at highest risk. 78% of unsupplemented, breast-fed, Iowa infants had levels less than 11 ng/mL during winter. For those who wonder how vitamin D could be important for brain development—given its very low levels in breast milk—Professors Hollis and Wagner of the Medical University of South Carolina discovered that breast milk is a source of vitamin D that is rich enough to maintain healthy levels in infants—provided the mothers took at least 4,000 units/day. Pregnant women who do not go out into the sun need more vitamin D than is in their prenatal vitamin—much more. Ziegler EE, Hollis BW, Nelson SE, Jeter JM. Vitamin D deficiency in breastfed infants in Iowa. Pediatrics. 2006 Aug;118(2):603–10. Hollis BW, Wagner CL. Vitamin D requirements during lactation: high-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1752S–8S.
In 2002, Dr. Shanna Nesby-O'Dell and her colleagues at the CDC found that almost 50% of young, black women of childbearing age had vitamin D levels lower than 15 ng/mL. 12% of black women had levels less than 10 ng/mL, compared to 0.5% of white women. While it is unknown if such low levels approach those seen in the brain-injury animal studies reviewed above, the levels in these young black women are close to undetectable. It may be that white children have a huge, developmental advantage over black children—an advantage that begins immediately after conception. One that has nothing to do with innate ability and everything to do with environment. 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 Jul;76(1):187–92.» page: autism index 1 2 3 4 5 6 7 8 9 10 11