New York, Mar 9: Possessing one or another version of a gene key to metabolizing the B vitamin folate may make a big difference in who responds to vitamin supplements intended to treat negative symptoms of schizophrenia, according to a new study. Researchers tracked 140 people with schizophrenia for 16 weeks and found that those with the so-called high-functioning FOLH1 gene variant had a greater response to folic acid and B12 supplements, compared to those with the low-functioning FOLH1 variant. (agencies)