Autism and Vitamin D during pregnancy

[jim mcnamara]

A A E Vinkhuyzen et al. Gestational vitamin D deficiency and autism-related traits: the Generation R Study, Molecular Psychiatry (2016). DOI:[/PLAIN] 10.1038/mp.2016.213

Interesting new study that indicates vitamin D is required for normal neurological development. It has been known for a long time that vitamin D (somewhat more like a hormone than a true vitamin, as it is not a co-enzyme constituent) is important for bone health, for example. Now it seems that dietary vitamin D is required during pregnancy. Direct sun exposure which creates vitamin D precursors in human skin was not recommended by the authors, because of skin cancer concerns.

abstract:

There is intense interest in identifying modifiable risk factors associated with autism-spectrum disorders (ASD). Autism-related traits, which can be assessed in a continuous fashion, share risk factors with ASD, and thus can serve as informative phenotypes in population-based cohort studies. Based on the growing body of research linking gestational vitamin D deficiency with altered brain development, this common exposure is a candidate modifiable risk factor for ASD and autism-related traits. The association between gestational vitamin D deficiency and a continuous measure of autism-related traits at ~6 years (Social Responsiveness Scale; SRS) was determined in a large population-based cohort of mothers and their children (n=4229). 25-hydroxyvitamin D (25OHD) was assessed from maternal mid-gestation sera and from neonatal sera (collected from cord blood). Vitamin D deficiency was defined as 25OHD concentrations less than 25 nmol l−1. Compared with the 25OHD sufficient group (25OHD>50 nmol l−1), those who were 25OHD deficient had significantly higher (more abnormal) SRS scores (mid-gestation n=2866, β=0.06, P<0.001; cord blood n=1712, β=0.03, P=0.01). The findings persisted (a) when we restricted the models to offspring with European ancestry, (b) when we adjusted for sample structure using genetic data, (c) when 25OHD was entered as a continuous measure in the models and (d) when we corrected for the effect of season of blood sampling. Gestational vitamin D deficiency was associated with autism-related traits in a large population-based sample. Because gestational vitamin D deficiency is readily preventable with safe, cheap and accessible supplements, this candidate risk factor warrants closer scrutiny.

[IMO]
For the US:

This might be explanatory for the differential distribution of autism rates among populations in the US. 3.8% fat milk in the US is the only commercially available milk with added vitamin D. Because of the somewhat misplaced guidance about fat consumption, higher SES* women have tended to avoid whole milk.

At the same time, they also inadvertently avoided getting extra vitamin D.

Other sources of vitamin D are salmon, tuna, beef liver, egg yolks. Again, eggs were on the no-eat list for cholesterol reasons. Which advice has been largely reverted. Beef liver consumption in the US is minuscule. Mostly ends up in pet foods.

This could help to explain why autism rates are higher in places where a lot of high SES women live. Silicon Valley is an example in the US. BTW there are good fatty acids in the diet, and they are required.

*SES Socioeconomic Status
[/IMO]

 

[Fervent Freyja]

Thanks for posting, I've recently been interested in the topic! This makes sense to me, here is another study, Vitamin D improves myelination after nerve injury: https://www.ncbi.nlm.nih.gov/pubmed/23741446

 

[256bits]

Direct sun exposure which creates vitamin D precursors in human skin was not recommended by the authors, because of skin cancer concerns

Another reason to get that Vitamin D.
https://www.ncbi.nlm.nih.gov/pubmed...nel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

This study, with similar methods and a longer follow-up, confirms the finding that sun exposure prior to diagnosis of melanoma is associated with improved survival

http://www.webmd.com/cancer/news/20080107/sunlight-good-bad-cancer-risk#1

If you are deficient in vitamin D, getting a little sun may actually reduce your risk of dying from certain non-skin cancers, according to a new report. And that benefit may outweigh the risk of getting skin cancer.

 

[Fervent Freyja]

Another reason to get that Vitamin D.
https://www.ncbi.nlm.nih.gov/pubmed...nel.Pubmed_DefaultReportPanel.Pubmed_RVDocSumhttp://www.webmd.com/cancer/news/20080107/sunlight-good-bad-cancer-risk#1

I will be feeling a little less guilty when I start tanning again!

This could help to explain why autism rates are higher in places where a lot of high SES women live. Silicon Valley is an example in the US. BTW there are good fatty acids in the diet, and they are required.
[/IMO]

This may be because women with higher SES have children later than those with lower SES. There is a large body of evidence showing that the risk of autism increases with the mothers age at pregnancy. https://www.ncbi.nlm.nih.gov/pubmed/27858958

 

[jim mcnamara]

There is no good way to test what I posited as an opinion, really. A nutrition researcher friend told me: 'Humans are the worst possible research subjects'
Compound that with business interests messing with science: http://www.pbs.org/newshour/rundown/sugar-industry-artificially-sweetened-harvard-research/
Not to mention the FUD attacks from the business lobby and political folks working to quash all kinds of other research that does not match their personal views.
FUD: https://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt

Note: the wiki article needs editing to remove some speculative stuff. Both sides of the FUD issue have problems it seems. ... what a surprise. The definition of the concept there is fine.