104 The nutrition handbook for food processors for calcium deficiency in i,.porosis, the weight of evidence points towards a role plements in preventing oste ts genesis and for calcium therapy in its prevention and management, at least in postmenopausal women(Heaney, 2001). Increases in bone mineral density(BMD)have been observed following calcium supplemen tation in young, as well as in elderly subjects. However, although dietary calcium does play a major role in optimisation of bone mineralisation it is by no means the only factor involved(Prentice, 1997) 4.5.4 Recommended intakes of calcium There is at present no international consensus regarding calcium requirements and levels in the diet necessary to meet optimum requirements Recommended intakes differ widely between countries, partly because different methods have been used to arrive at the recommendations. While some authorities have focused on meeting nutritional requirements, others have aimed at optimising bone density (Wynne, 1998). There is also the fact that actual intakes of calcium vary widely world-wide, without, in many cases, an apparent effect on bone develop- ment. In parts of Africa and Asia intake of dietary calcium is as low as 300- 400 mg/day, while in Northern Europe it can be 1500mg/day or more In the UK the Panel for Dietary Reference Values of COMA(the Committee on Medical Aspects of Food Policy) of the Department of Health, while noting the difficulty of assessing the adequacy of the dietary supply of calcium, has established RNIs for calcium for different groups in the population(Department of Health, 1991). Since the panels experts found that no single approach to the estimation of these values was considered to be satisfactory, these intakes are not onsidered to represent true basal dietary requirements, but rather to describe the apparent calcium requirements of healthy people in the UK under prevailing leary The UK RNi for adults age ged 19-50 years is 700 mg/day, with an additional 550mg/day for lactating women. In the US an intake of 1000 mg/day is recom- ge group, with no additional Institute of Medicine, Food and Nutrition Board, 1998). In contrast, WHO/FAO in 1974 proposed 400-500 mg/day for this group, with additional intakes for pregnant and lactating women. 4.5.5 Dietary sources of calcium Milk and dairy products are the major sources of calcium in many diets In coun ries such as the UK where addition of calcium to flour is required by law, bread and other cereal products also make an important contribution to intake Sardines and other small fish, which are eaten whole, are also good sources. In countries where dairy products are not used in quantity and where fortification of flour is not required, requirements may be met by green leafy vegetables, roots, nuts and pulses. Where domestic water is hard, with a high calcium content, it can make a significant contribution to intake.plements in preventing osteoporosis, the weight of evidence points towards a role for calcium deficiency in its genesis and for calcium therapy in its prevention and management, at least in postmenopausal women (Heaney, 2001). Increases in bone mineral density (BMD) have been observed following calcium supplemen￾tation in young, as well as in elderly subjects. However, although dietary calcium does play a major role in optimisation of bone mineralisation it is by no means the only factor involved (Prentice, 1997). 4.5.4 Recommended intakes of calcium There is at present no international consensus regarding calcium requirements and levels in the diet necessary to meet optimum requirements. Recommended intakes differ widely between countries, partly because different methods have been used to arrive at the recommendations. While some authorities have focused on meeting nutritional requirements, others have aimed at optimising bone density (Wynne, 1998). There is also the fact that actual intakes of calcium vary widely world-wide, without, in many cases, an apparent effect on bone develop￾ment. In parts of Africa and Asia intake of dietary calcium is as low as 300– 400 mg/day, while in Northern Europe it can be 1500 mg/day or more. In the UK the Panel for Dietary Reference Values of COMA (the Committee on Medical Aspects of Food Policy) of the Department of Health, while noting the difficulty of assessing the adequacy of the dietary supply of calcium, has established RNIs for calcium for different groups in the population (Department of Health, 1991). Since the panel’s experts found that no single approach to the estimation of these values was considered to be satisfactory, these intakes are not considered to represent true basal dietary requirements, but rather to describe the apparent calcium requirements of healthy people in the UK under prevailing dietary circumstances. The UK RNI for adults aged 19–50 years is 700 mg/day, with an additional 550 mg/day for lactating women. In the US an intake of 1000 mg/day is recom￾mended for the same age group, with no additional allowance for lactation (Institute of Medicine, Food and Nutrition Board, 1998). In contrast, WHO/FAO in 1974 proposed 400–500 mg/day for this group, with additional intakes for pregnant and lactating women. 4.5.5 Dietary sources of calcium Milk and dairy products are the major sources of calcium in many diets. In coun￾tries such as the UK where addition of calcium to flour is required by law, bread and other cereal products also make an important contribution to intake. Sardines and other small fish, which are eaten whole, are also good sources. In countries where dairy products are not used in quantity and where fortification of flour is not required, requirements may be met by green leafy vegetables, roots, nuts and pulses. Where domestic water is ‘hard’, with a high calcium content, it can make a significant contribution to intake. 104 The nutrition handbook for food processors