Written by Tatjana Djakovic, Staff Writer. A large long term study showed that a group of mothers with highest blood levels had 83% better scores in attention switching, a factor in autism scores.

Vitamin D is important during pregnancy for the mother, as well as for the healthy development of the child. During pregnancy, extra calcium is required for the growth of the fetus which increases the need for maternal vitamin D. Adequate vitamin D levels during pregnancy decrease the risks of eclampsia (dangerously high blood pressure), gestational diabetes and increased need for caesarean sections (1). Despite its importance, vitamin D deficiency (characterized by levels of less than 25 nmol of 25(OH) vitamin D, which is a measurable form of vitamin D) is still highly prevalent in pregnant women (2).

Epidemiological observations have shown that autism is more prevalent in the offspring of pregnancies in which the first and second trimester occurred during the winter and spring months marked lower sunlight exposure (3)

A recent study attempted to analyze the relationship between low levels of vitamin D in the pregnant mothers and the incidence of autism and autistic like behavior. The study took place over a 20 year period, in which the blood samples of 929 randomly selected pregnant women at King Edward Memorial Hospital in Australia were collected during the 16 and 20 weeks of pregnancy between May 1989 and November 1991. The serum from the collected blood samples was stored at -80°C; this type of storage has been shown to keep the sample stable for over three decades (4) and the vitamin D blood levels were measured in June 2011. The follow ups were performed at the 5, 8, 10, 14 and 17 years. The autistic like traits were assessed using Autism Spectrum Quotient (AQ) survey divided into five categories: social skills, communication, imagination, attention to detail and attention switching. A higher score was indicative of autistic behavior (5).

After a period of 20 years, 406 offspring (male = 149, female =257) completed the survey in the early adulthood. The results indicated that the attention switching category of the test was performed more poorly by the offspring of mothers that were deficient in vitamin D during their pregnancy. This relationship remained significant after adjustment for sociodemographic factors.

Tertile 1 (Lowest Vitamin D) Tertile 2 Tertile 3 (Highest Vitamin D) % Improvement in High Material Vitamin D P value
Attention Switching Score 12 2 2 83.3 0.01

 

However, the study did not show a statically significant relationship between materal vitamin D and other categories in the Autism Spectrum Quotient survey. For the future study, authors suggest studying vitamin D levels in pregnant women who have an existing child with autism, since sibling fetuses are at higher risk and examine the prevalence of autism and autistic like behavior (5). This is a promising study on the importance of vitamin D and the risk of autism and needs to be further analyzed since the biological functions of vitamin D are important to healthy brain development of a fetus (6).

Source: Whitehouse, Andrew JO, et al. “Maternal vitamin D levels and the autism phenotype among offspring.” Journal of autism and developmental disorders 43.7 (2013): 1495-1504.

© 2017 Springer International Publishing AG.

Posted December 6, 2013.

References:

  1. Lewis, Sharon, et al. “Vitamin D deficiency and pregnancy: from preconception to birth.” Molecular nutrition & food research 54.8 (2010): 1092-1102.
  2. McAree, Trixie, et al. “Vitamin D deficiency in pregnancy–still a public health issue.” Maternal & child nutrition 9.1 (2013): 23-30.
  3. Gardener, H., et al., “Prenatal risk factors for autism: Comprehensive meta-analysis.” British Journal of Psychiatry. (2009): 18(4), 287-304.
  4. Corder, E. H., et al., “Vitamin D and préstate cancer: a prediagnostic study with stored sera.” Cancer Epidemiology, Biomarkers and Prevention. (1993). 2(5), 467-472.
  5. Whitehouse, Andrew JO, et al. “Maternal Vitamin D Levels and the Autism Phenotype Among Offspring.” Journal of autism and developmental disorders (2012): 1-10.
  6. Brown, Jillanne, et al. “1, 25-Dihydroxyvitamin D< sub> 3 induces nerve growth factor, promotes neurite outgrowth and inhibits mitosis in embryonic rat hippocampal neurons.” Neuroscience letters 343.2 (2003): 139-143