The effect of · iron supplementation on maximal oxygen consumption in boys aged 9 11 years with iron deficiency and anaemia
Iron deficiency anaemia is the most common abnormality of the blood in childhood (Karabus 1987). If the quantity of iron lost by the body exceeds iron intake, the body will draw on its iron reserves to counterbalance this deficit. However, the continuance of an iron imbalance will eventually lead to a reduction in body iron stores. Because iron forms an integral component of the oxygen transport mechanism of the body, it is understandable that the functional capacity of this system will be compromised under conditions of iron deficiency. A deficit in oxygen transport capacity will presumably indicate a decreased capacity to persevere in the face of continuing strenuous physical activity. The decrement in physical aerobic working capacity (maximal oxygen consumption) will largely be indicative of the decrease in oxygen transport capacity. Routine haemoglobin determinations carried out in the outpatient department of the Red Cross War Memorial Children's Hospital in Cape Town showed that many Coloured and African pre-schoolgoing children had abnormally low haemoglobin levels which occurred as a manifestation of iron deficiency anaemia (Lanzkowsky 1961). In another similar but more recent study also in the Cape Peninsula, Lamparelli et al. (1988) showed that the prevalence of iron deficiency anaemia in Coloured and African children was 15.5 % and 36.0 %, respectively . In this study, the condition of iron deficiency anaemia was particularly pronounced in urban Coloured children. In both these studies done in the Western Cape, the majority of Coloured children were classified as coming from the lowest socioeconomic income group in the community. In the majority of studies concerning the relationship between socioeconomic status and iron deficiency anaemia, it is often stated that low socioeconomic circumstances are significantly correlated to low blood haemoglobin levels (Expert Scientific Working Group 1985; Lanzkowsky 1959; Lanzkowsky 1961; World Health Organization 1972; World Health Organization 1975).