Folic acid deficiency and hypotonia

There is disagreement whether or not folic acid is actually a cause of infantile hypotonia. In one instance a breast fed infant was admitted with hypotonia and serum folic acid levels between 0 and 4 ng/ml. Vitamin B12 deficiency, hemolytic anemia, liver disease, and rickets were ruled out after extensive testing. However, a well-nourished lactating mother should supply adequate vitamin B supplies to her infant. It was also unclear whether malabsorption or hemolysis was the cause of this deficiency since the reported slightly elevated SGOT and lactic dehydrogenase could be related to hemolysis.