About the Authors

David S. Wald

d.s.wald@qmul.ac.uk

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom

Joan K. Morris

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom

Nicholas J. Wald

Affiliation Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine, Queen Mary University of London, London, United Kingdom

Competing Interests

Nicholas Wald jointly holds a European patent (EU1272220) for a combination pill for the prevention of cardiovascular disease (patent pending in USA and Canada), in which folic acid is an optional component and together with David Wald has an interest in its development. This does not alter the authors' adherence to all PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: DW JK NW. Performed the experiments: DW JK NW. Analyzed the data: DW JK MW. Contributed reagents/materials/analysis tools: JM. Wrote the paper: DS JM NW.