The American Academy of Pediatrics Committee on Genetics thanks Dr Herbert for his comments, and would like to address his concerns as follows.
Pernicious anemia. There are few data in the literature that address the issue of folic acid and vitamin B12 deficiency. Estimates suggest that the masking of pernicious anemia by folate rarely takes place with an intake of folate < 5 mg per day. On the other hand, there is evidence that a number of individuals with vitamin B12 deficiency have neurological symptoms without any anemia.