Eighty iron-deficient, nonpregnant female workers were randomly assigned to ferrous sulphate (60 or 120 mg Fe/d) or placebo treatment for 12 wk. Energy expenditure was estimated during 3 d by heart rate (HR) recording. Production efficiency (PE) was calculated as the ratio of productivity to energy expenditure. In the iron-treated group mean hemoglobin (Hb) increased from 114 to 127 g/L (P < 0.001), mean serum ferritin increased from 9.7 to 30.0 micrograms/L (P < 0.001), and mean free erythrocyte protoporphyrin decreased from 1.01 to 0.49 mumol/L (P < 0.001). Mean HR at work decreased from 95.5 to 91.1 beats/min (P < 0.001), which was inversely correlated with the change in Hb (r = -0.60, P < 0.001). PE increased significantly in the iron-treated group (P < 0.001) and its change paralleled the change in Hb (r = 0.58, P < 0.001). The results show that iron supplementation enabled these women to do the same work at a lower energy cost.

The present study investigates the prevalence and type of anaemia in Chinese female cotton mill workers. The prevalence of anaemia is reported in 447 non-pregnant female workers aged between 19 and 45 years. The mean value for haemoglobin (Hb) was 123 (SD 15) g/1 and 150 of the total 447 subjects had Hb values below 120 g/l; thus 34% of the population was anaemic according to World Health Organization (WHO, 1975) criteria. The mean value for free erythrocyte protoporphyrin (FEP) was 419 (SD 215) pg/l; 55 % of the total population had F E P values higher than 350 pg/l and 72 YO among the anaemic subjects. Serum ferritin (SF) was tested in all the women with a H b value less than 120 g/l and 71 % of them had SF values below 12.0 pg/l. Eighty women diagnosed as either Fe deficient or with Fedeficient anaemia were selected for a diagnostic supplementation trial. They were randomly assigned to FeSO, (60 or 120 mg Fe/d) or placebo treatment for 12 weeks. Fe supplementation increased mean Hh values from 114 to 127 g/l (P < 0,001) and SF levels from 9.7 to 30.0 pg/l (P < O.OOl), and decreased mean FEP values from 570 to 277 pg/1 (P < 0.001). The response rate of H h in the whole Fe-treated group or Fe-treated subjects with an H b level less than 120 g/1 was 90% or 92% respectively. These findings indicate that the type of anaemia in this population was mainly Fe deficiency. It was also found that in this population the severity of anaemia, not the prevalence, was significantly related to the use of intra-uterine devices (IUD). Anaemia: Iron: Chinese female workers China has the largest female work force in the world. Women, who constitute about 40