Lowering blood homocysteine with folic acid based supplements: meta-analysis of randomised trials od Brattstrom, L, Landgren, F, Israelsson, B, Lindgren, A, Hultberg, B, Andersson, A, Cuskelly, G, McNulty, H, Strain, S, McPartlin, J, Weir, D, Scott, J, den Heijer, M, Brouwer, I, Blom, H, Bos, G, Spaans, A, Rosendaal, F, Thomas, C, Haak, H, Wijermans, P, Gerrits, W, Naurath, H, Joosten, E, Riezler, R