The use of Blood Concentrations of Vitamins and their Respective Functional Indicators to Define Folate and Vitamin B12 Status

In recent years there has been growing interest in the vitamins folic acid and vitamin B12 because of the realization that the status of these vitamins in populations is less than adequate, and that such inadequacy may be linked to adverse public health outcomes. This concern has prompted the United States, Canada, and other countries to fortify grain products with folic acid, while additional countries are considering doing so in the near future. This presentation provides a new approach which relies on the combination of the concentrations in blood of vitamins and their respective functional indicators to establish cutoff points for assessing folate and vitamin B12 status in populations. The premise is based on the fact that the relationship between plasma vitamin concentrations and their respective functional indicators is inverse and biphasic, with a steep slope at low concentrations of the vitamin and a more moderate slope at higher plasma vitamin concentrations. We propose that the intersection of t...