The Work and Iron Status Evaluation (WISE) study in Indonesia provided randomly chosen men and women in rural Indonesia with regular iron supplementation for several months, while the comparison group received a placebo.28 The study found that the iron supplements made the men able to work harder, and the resulting increase in their income was many times the cost of a yearly supply of iron-fortified fish sauce. A year’s supply of the fish sauce cost $7 USD PPP, and for a self-employed male, the yearly gain in earnings was $46 USD PPP—an excellent investment.
