IRON supplements are still prescribed by some doctors during pregnancy to prevent anaemia, but the latest research shows they are not necessary - provided the woman is eating a normal diet. A study of 12 pregnant women at the Royal Victoria Infirmary, Newcastle upon Tyne, has shown that during a normal pregnancy the body increases its absorption of iron from food to meet the extra requirements. There is evidence that iron supplements may be harmful, the authors point out in the British Medical Journal. Iron-rich foods include red meat, green vegetables and shellfish.