Effects of vitamin B12, folate, and vitamin B6 supplements in elderly people with normal serum vitamin concentrations.
Naurath HJ, Joosten E, Riezler R, Stabler SP, Allen RH, Lindenbaum J. Effects of vitamin B12, folate, and vitamin B6 supplements in elderly people with normal serum vitamin concentrations. Lancet. 1995 Jul 08; 346(8967):85-9.