ASPartOfMe wrote:
It is saying that Autistic children who are on gluten-free or casein-free diets have deficits in calcium and vitamin D. Supplements don't make up for these deficits. The study conclusions were about these specific issues. The study did not come to any conclusions about whether these diets are good or bad overall.
But it says, "Overall, researchers found that
kids with autism were consuming typical levels of micronutrients and they had deficiencies in vitamins D and E, calcium, potassium and choline
similar to what’s seen in children generally."
So, they have problems, but only the same problems other kids have. (It's a little unclear, so this sentence could be refering to all autistic kids including the ones who don't have a special diet, but if that's the case then they didn't include any info about what they found regarding kids who do have a special diet.)
The part about multi-vitamin supplements causing higher-than-healthy levels of some nutrients was useful info, but that was just about supplements instead of diet, and it didn't give any non-autism info for comparison. So it doesn't really imply anything about autism diets. It sounds like you should get the kid's vitamin levels checked so that you can supplement appropriately instead of using a one-size-fits-all multivitamin. That's probably a good idea for anyone, regardless of diet. The article provides a couple nutrients where a casein-free gluten-free diet is advantageous, but ultimately ends up listing zero downsides of a special diet compared to an unrestricted diet.