Calcium and Vitamin D Supplement Prescribing Practices among Providers Caring for Children with Autism Spectrum Disorders: Are We Addressing Bone Health?

Gluten and Autism Spectrum Disorder

An expanding body of literature is examining connections between Autism Spectrum Disorder (ASD) and dietary interventions. While a number of specialist diets have been suggested as beneficial in ASD, gluten has received particularly close attention as a potentially exacerbating factor. Reports exist suggesting a beneficial effect of the gluten-free diet (GFD) in ameliorating behavioural and intellectual problems associated with ASD, while epidemiological research has also shown a comorbidity between ASD and coeliac disease. However, both caregivers and clinicians have expressed an uncertainty of the value of people with ASD going gluten-free, and as the GFD otherwise receives considerable public attention a discussion which focuses specifically on the interaction between ASD and gluten is warranted. In this review we discuss the historical context of ASD and gluten-related studies, and expand this to include an overview of epidemiological links, hypotheses of shared pathological mechanisms, and ultimately the evidence around the use and adoption of the GFD in people with ASD.

Social behaviors and contextual memory of Vcp mutant mice are sensitive to nutrition and can be ameliorated by amino acid supplementation

Both genetic variations and nutritional deficiency are associated with autism spectrum disorders and other neurological disorders. However, it is less clear whether or how nutritional deficiency and genetic variations influence each other under pathogenic conditions. "Valosin-containing protein" (VCP, also known as p97) is associated with multiple neurological disorders and regulates dendritic spine formation by controlling endoplasmic reticulum formation and protein synthesis efficiency. Increased protein synthesis ameliorates the dendritic spine defects of Vcp-deficient neurons. Therefore, we investigated if Vcp-deficient mice are sensitive to nutritional conditions. Here, we show that social interaction and contextual memory of Vcp-deficient mice are indeed influenced by different dietary protein levels. Moreover, leucine supplementation ameliorates the behavioral deficits and dendritic spine density of Vcp-deficient mice, strengthening evidence for the role of protein synthesis in VCP function. Our study illustrates that genetic variation and nutrient factors cross-talk to influence neuronal and behavioral phenotypes.

Bone Mineral Density in Boys Diagnosed with Autism Spectrum Disorder: A Case-Control Study

This study compared bone mineral density (BMD) of the spine obtained by dual-energy X-ray absorptiometry (DEXA), nutritional status, biochemical markers, and gastrointestinal (GI) symptoms in 4-8 year old boys with Autism Spectrum Disorder (ASD) with a group of age-matched, healthy boys without ASD. Boys with ASD had significantly lower spine BMD compared to controls but this was not correlated with any biochemical markers, dietary intake of calcium and vitamin D, elimination diet status, or GI symptomology. Reduced BMD in 4-8 year old boys with ASD appears to involve factors other than nutrient intake and GI status, and requires further study.

Bone microarchitecture in adolescent boys with autism spectrum disorder

BACKGROUND

Boys with autism spectrum disorder (ASD) have lower areal bone mineral density (aBMD) than typically developing controls (TDC). Studies of volumetric BMD (vBMD) and bone microarchitecture provide information about fracture risk beyond that provided by aBMD but are currently lacking in ASD.

OBJECTIVES

To assess ultradistal radius and distal tibia vBMD, bone microarchitecture and strength estimates in adolescent boys with ASD compared to TDC.

DESIGN/METHODS

Cross-sectional study of 34 boys (16 ASD, 18 TDC) that assessed (i) aBMD at the whole body (WB), WB less head (WBLH), hip and spine using dual X-ray absorptiometry (DXA), (ii) vBMD and bone microarchitecture at the ultradistal radius and distal tibia using high-resolution peripheral quantitative CT (HRpQCT), and (iii) bone strength estimates (stiffness and failure load) using micro-finite element analysis (FEA). We controlled for age in all groupwise comparisons of HRpQCT and FEA measures. Activity questionnaires, food records, physical exam, and fasting levels of 25(OH) vitamin D and bone markers (C-terminal collagen crosslinks and N-terminal telopeptide (CTX and NTX) for bone resorption, N-terminal propeptide of Type 1 procollagen (P1NP) for bone formation) were obtained.

RESULTS

ASD participants were slightly younger than TDC participants (13.6 vs. 14.2years, p=0.44). Tanner stage, height Z-scores and fasting serum bone marker levels did not differ between groups. ASD participants had higher BMI Z-scores, percent body fat, IGF-1 Z-scores, and lower lean mass and aBMD Z-scores than TDC at the WB, WBLH, and femoral neck (P<0.1). At the radius, ASD participants had lower trabecular thickness (0.063 vs. 0.070mm, p=0.004), compressive stiffness (56.7 vs. 69.7kN/mm, p=0.030) and failure load (3.0 vs. 3.7kN, p=0.031) than TDC. ASD participants also had 61% smaller cortical area (6.6 vs. 16.4mm2, p=0.051) and thickness (0.08 vs. 0.22mm, p=0.054) compared to TDC. At the tibia, ASD participants had lower compressive stiffness (183 vs. 210kN/mm, p=0.048) and failure load (9.4 vs. 10.8kN, p=0.043) and 23% smaller cortical area (60.3 vs. 81.5mm2, p=0.078) compared to TDC. A lower proportion of ASD participants were categorized as "very physically active" (20% vs. 72%, p=0.005). Differences in physical activity, calcium intake and IGF-1 responsiveness may contribute to group differences in stiffness and failure load.

CONCLUSION

Bone microarchitectural parameters are impaired in ASD, with reductions in bone strength estimates (stiffness and failure load) at the ultradistal radius and distal tibia. This may result from lower physical activity and calcium intake, and decreased IGF-1 responsiveness.