Your child is unsocial, moody, and not hitting standard development milestones. Is it autism? A developmental disability? Or could it be as simple as B12 deficiency? Millions of children and adolescents are at risk of developing serious neurological disorders caused by B12 deficiency, yet B12 deficiency often goes misdiagnosed as autism, depression, and mental illness. B12 deficiency is treatable?but if you don’t catch B12 deficiency in time, it can cause permanent nerve damage and disability.