44 The nutrition handbook for food processors The apparent protection of a diet high in fruit and vegetables is likely to be the result of a multifactorial effect from a number of components in those foods Two recent prospective studies found that subjects entering the studies with higher plasma B-carotene concentrations from dietary intake had a lower risk of lung cancer(McDermott, 2000). This finding perhaps suggests more studies using dietary enrichment with carotenoids rather than pharmacological supplements should be carried out 3.7 Safety of vitamin A and B-carotene 3.7.1 Safety of retinol Symptoms of hypervitaminosis A may occur in the skin, nervous system, mus- culoskeletal, circulatory systems or in internal organs. Toxicity varies with the dose, body mass, age, sex, disease conditions, concurrent drugs being taken and environmental chemical exposure(Blomhoff, 2001). Toxicity is rare from natural diets, the exception is from high intakes of liver (3-5mg/100g)(Northrop- Clewes, 2001b). Fortified foods are used in industrialised countries and can be consumed excessively(e.g. children may consume several bowls of breakfast ereal a day ) Supplements, i.e. multiple micro-nutrients containing vitamin A are readily available in industrialised countries and the usual content 500ug RE non-pregnant, non-lactating women 1000ug RE pregnant/lactating women. 750ug RE for children 5 years However, in general, healthy individuals in industrialised countries should need supplements, as eating a balanced diet should provide all the nutrients required. In contrast, VAD is common among women of reproductive age livin in deprived conditions and may be associated with a substantial increase in mater- nal mortality. The immediate postpartum period represents an opportunity to provide such women with a large dose of vitamin A, which benefits both mother and child. Since 1982 WHO/UNICEF/IVACG have recommended supplement- ing postpartum women and their infants, where VADD are a public health Mothers: 2000001u 6 weeks post partum. Infants: 25000IU at 6. 10. 14 weeks and 100000lu at 9 months. However, theoretical calculations and recent data suggest the dose is too small and so in 2001, new WHO supplement recommendations were proposed Mothers: 200000IU at delivery 2000001u 6-8 weeks after delivery Infants: 50000IU at 6. 10. 14 weeks +1000001U 6-11 months + 200000IU every 4-6 months after 12 months Acute toxicity Acute hypervitaminosis A can be defined as any toxicity manifested following a single very high dose or several very high doses over a few days(BlomhoffThe apparent protection of a diet high in fruit and vegetables is likely to be the result of a multifactorial effect from a number of components in those foods. Two recent prospective studies found that subjects entering the studies with higher plasma b-carotene concentrations from dietary intake had a lower risk of lung cancer (McDermott, 2000). This finding perhaps suggests more studies using dietary enrichment with carotenoids rather than pharmacological supplements should be carried out. 3.7 Safety of vitamin A and b-carotene 3.7.1 Safety of retinol Symptoms of hypervitaminosis A may occur in the skin, nervous system, mus￾culoskeletal, circulatory systems or in internal organs. Toxicity varies with the dose, body mass, age, sex, disease conditions, concurrent drugs being taken and environmental chemical exposure (Blomhoff, 2001). Toxicity is rare from natural diets, the exception is from high intakes of liver (3–5 mg/100 g) (Northrop￾Clewes, 2001b). Fortified foods are used in industrialised countries and can be consumed excessively (e.g. children may consume several bowls of breakfast cereal a day). Supplements, i.e. multiple micro-nutrients containing vitamin A, are readily available in industrialised countries and the usual content is: • 1500mg RE non-pregnant, non-lactating women. • 1000mg RE pregnant/lactating women. • 750mg RE for children < 5 years. However, in general, healthy individuals in industrialised countries should not need supplements, as eating a balanced diet should provide all the nutrients required. In contrast, VAD is common among women of reproductive age living in deprived conditions and may be associated with a substantial increase in mater￾nal mortality. The immediate postpartum period represents an opportunity to provide such women with a large dose of vitamin A, which benefits both mother and child. Since 1982 WHO/UNICEF/IVACG have recommended supplement￾ing postpartum women and their infants, where VADD are a public health problem, with: • Mothers: 200 000 IU < 6 weeks post partum. • Infants: 25 000 IU at 6, 10, 14 weeks and 100 000 IU at 9 months. However, theoretical calculations and recent data suggest the dose is too small and so in 2001, new WHO supplement recommendations were proposed: • Mothers: 200 000 IU at delivery + 200 000 IU < 6–8 weeks after delivery • Infants: 50 000 IU at 6, 10, 14 weeks + 100 000 IU 6–11 months + 200 000 IU every 4–6 months after 12 months. Acute toxicity Acute hypervitaminosis A can be defined as any toxicity manifested following a single very high dose or several very high doses over a few days (Blomhoff, 44 The nutrition handbook for food processors