Vitamin D Deficiency At Birth May Increase Risk of Autism and Schizophrenia

Studies involving thousands of people have shown that babies born with low levels of vitamin D are at increased risk of developing disorders such as ADHD, schizophrenia and autism. This suggests that ensuring good levels of vitamin D from birth may help protect mental health throughout life.

Vitamin D is an essential substance for the human body and plays an important role not only in bone health, but also in the proper functioning of the brain and immune system.

Recent studies suggest that adequate levels of vitamin D from birth may help protect the developing brain and possibly reduce the risk of some psychiatric and neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD), schizophrenia and autism spectrum disorder (ASD).

The explanation for this link lies in how vitamin D influences the formation of brain connections and the regulation of inflammation, in addition to interacting with genes important for neurological development.

In this Danish study, researchers sought to better understand how two markers related to vitamin D-25-hydroxyvitamin D (25[OH]D), which is the most commonly used form of vitamin D measurement in the blood, and vitamin D-binding protein (DBP), which transports vitamin D in the body, are associated with the risk of developing various mental disorders.

To do this, they used a massive database of nearly 89,000 people born between 1981 and 2005 in Denmark. The health data included diagnoses of major depression, bipolar disorder, schizophrenia, ADHD, ASD, and anorexia nervosa, made according to ICD-10 criteria (an international medical classification).

The team measured levels of vitamin D and vitamin D-binding protein in blood samples taken at birth (dried blood spots, like the heel prick test) and correlated them with diagnoses made years later.

The study found that lower levels of vitamin D were linked to a higher risk of developing schizophrenia, ADHD, and ASD. For example, for schizophrenia, each increase in vitamin D levels reduced the risk by about 18%. In addition, lower levels of vitamin D-binding protein were also associated with an increased risk of schizophrenia.

The researchers also performed genetic analyses. Using polygenic risk scores, which indicate a person’s genetic propensity for certain levels of vitamin D, they found that even when adjusting for vitamin D-binding protein, higher levels of vitamin D were associated with a lower risk of schizophrenia and ASD.

To reinforce these findings, they used a technique called Mendelian randomization, which helps understand whether there is a cause-and-effect relationship, and found evidence that low levels of vitamin D at birth could actually cause a higher risk of ADHD.

These results suggest that taking care of vitamin D levels during pregnancy and early life may be an effective preventative measure against certain mental disorders.

While more research is needed to turn this into a universal medical recommendation, the study reinforces the importance of public policies that ensure adequate levels of vitamin D from birth, whether through supplementation or nutritional guidance for pregnant women and newborns.

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Convergent evidence linking neonatal vitamin D status and risk of neurodevelopmental disorders: a Danish case-cohort studyHenriette Thisted Horsdal, Clara Albiñana, Zhihong Zhu,  Sanne, Grundvad Boelt, 

Nis Borbye-Lorenzen, Arieh S Cohen, Kristin Skogstrand, Lars Melgaard, 

Nadia Jensen MacSweenl, Marta Jadwiga Thorbek, Oleguer Plana-Ripoll, Liselotte Vogdrup Petersen, Cynthia M Bulik, Anders D B⊘rglum, 

Ole Mors, Merete Nordentoft, Thomas Werge, Gunn-Helen Moen, 

Shannon D’Urso, Naomi R Wray, Bjarni J Vilhjálmsson, Esben Agerbo, Carsten B⊘cker Pedersen, Preben Bo Mortensen, and John J McGrath

The Lancet Psychiatry, Volume 12, Issue 6, 410 - 420

Abstract:

There is growing evidence linking neonatal vitamin D deficiency to an increased risk of schizophrenia, ADHD, and autism spectrum disorder (ASD). The aim of this study was to examine the association between two vitamin D biomarkers (25 hydroxyvitamin D [25(OH)D] and vitamin D-binding protein [DBP], and their related genetic correlates) and the risk of six mental disorders. We used a population-based, case-cohort sample of all individuals born in Denmark between 1981 and 2005. Using Danish health registers with follow-up to Dec 31, 2012, we identified individuals diagnosed with major depressive disorder, bipolar disorder, schizophrenia, ADHD, ASD, and anorexia nervosa based on ICD-10 criteria. Additionally, a random subcohort from the general population was selected. Based on neonatal dried blood spots, we measured concentrations of 25(OH)D and DBP. Our primary analyses were based on hazard ratios (HR) with 95% CI and absolute risks for the six mental disorders according to measured concentrations of 25(OH)D and DBP. As secondary analyses, we examined the association between genetic predictors of 25(OH)D and DBP, and the six mental disorders, and Mendelian randomisation analyses based on published summary statistics for 25(OH)D, DBP, and the six mental disorders. People with lived experience contributed to the development of the guiding hypothesis. We used the total population from the iPSYCH2012 design (n=88 764), which included individuals who developed the six mental disorders, major depressive disorder (n=24 240), bipolar disorder (n=1928), schizophrenia (n=3540), ADHD (n=18 726), ASD (n=16 146), anorexia nervosa (n=3643), and the randomly sampled subcohort (n=30 000). Among those who met a range of inclusion criteria (eg, measured 25[OH]D, DBP or genotype, and predominantly European ancestry), we measured 25(OH)D or DBP in 71 793 individuals (38 118 [53·1%] male and 33 675 [46·9%] female); 65 952 had 25(OH)D and 66 797 the DBP measurements. Significant inverse relationships were found between 25(OH)D and schizophrenia (HR 0·82, 95% CI 0·78–0·86), ASD (HR 0·93, 95% CI 0·90–0·96), and ADHD (HR 0·89, 95% CI 0·86–0·92). A significant inverse relationship was found between DBP and schizophrenia (HR 0·84, 95% CI 0·80–0·88). Based on polygenic risk scores, higher concentrations of 25(OH)D (adjusted for DBP) were significantly associated with a reduced risk of both ASD and schizophrenia. Analyses based on Mendelian randomisation provided support for a causal association between both lower 25(OH)D and DBP concentrations and an increased risk of ADHD. Convergent evidence finds that neonatal vitamin D status is associated with an altered risk of mental disorders. Our study supports the hypothesis that optimising neonatal vitamin D status might reduce the incidence of a range of neurodevelopmental disorders.