An analysis of factors leading to a reduction in iron deficiency in Swedish women.

The prevalence of iron deficiency anaemia among Swedish women of child-bearing age has fallen markedly since the mid-1960s. At that time, population studies in Göteborg and Uppsala showed that iron deficiency anaemia was present in about 25-30% of women. Later, in population studies in Göteborg in 1968-69 and 1974-75, the prevalence in the same age group was found to have fallen to 6-7%. Several factors may explain the improved iron status. The level of iron fortification of flour was increased from 30 mg/kg of flour in 1943 to 65 mg in 1970, this increase adjusting the iron intake to compensate for the lower energy requirement and expenditure of present-day living habits. There has also been a marked increase in the intake of iron tablets and of tablets containing ascorbic acid.An analysis of various factors indicates that the 20-25% improvement in iron status can be accounted for by increased use of oral contraceptives (3-4%), the impact of increased iron fortification (7-8%), the widespread use of ascorbic acid supplements (3%), and greater prescribing of iron tablets (10%).This analysis of the factors leading to the marked reduction in the prevalence of iron deficiency anaemia among Swedish women may be useful to public health planners in other countries with similar problems. Our results indicate that several factors need to be considered when planning controlled field trials and evaluating the results obtained. The methods used to analyse the impact of different factors on the reduction in iron deficiency can also be used to predict the effects of various public health measures on the iron status of a population.