Effect of dose and formulation on iron tolerance in pregnancy

The National Nutritional Anaemia Prophylaxis Programme (NNAPP) in India was launched in 1971. However, anaemia continues to be a major public health problem. Partial coverage of the population, inadequate dose of the iron supplement, defective absorption due to intestinal infestations and problems with formulation have been recognized as factors responsible for its failure. Therefore, the bioavailability of iron from different formulations containing 60 mg of elemental iron and of tablets with varying doses of elemental iron was undertaken.

One hundred and fifteen women were randomly allotted to receive different formulations and doses of iron and then undergo iron tolerance tests. They received ferrous sulphate tablets containing 60 mg, 120 mg and 180 mg of elemental iron; formulations containing 60 mg of elemental iron as pure ferrous sulphate salt, ferrous fumarate tablets, ferrous fumarate syrup, excipients added to pure ferrous sulphate salts, powdered ferrous sulphate tablets, iron tablets distributed by the NNAPP and pure ferrous salt in gelatin capsules.

The data obtained from 32 subjects were excluded because of non-compliance, intolerance of the medication and lack of results of blood tests. Data from the remaining 83 subjects indicated that increasing the dose of elemental iron from 60 mg to 180 mg improved the bioavailability of iron, but was associated with unacceptable side-effects. Also, liquid formulations of iron had a better bioavailability, with ferrous fumarate syrup and gelatin capsules being the most superior.

Providing the iron formulation with a high bioavailability should enable the NNAPP to be more successful in decreasing the prevalence of anaemia.