Calcium

From FAO/WHO and Authors of Nutrition, verbatim:

FAO. 1974. Handbook on Human Nutritional Requirements. Rome, FAO.

It is nearly 30 years since the last FAO/WHO recommendations on calcium intake were published in 1974

 FAO/WHO Expert Group. 1962. Calcium Requirements. Rome, FAO.

and nearly 40 years since the experts’ meeting in Rome 

Albright, F. & Reifenstein, E.C. 1948. The Parathyroid Glands and Metabolic Bone Disease. Baltimore: Williams & Wilkins

on which these recommendations were based. During this generation gap, a paradigm shift has occurred with respect to the involvement of calcium in the aetiology of osteoporosis. The previous reports were written against the background of the Albright paradigm,

Nordin, B.E.C. 1960. Osteomalacia, osteoporosis and calcium deficiency. Clin. Orthop., 17: 235-258. 

according to which osteomalacia and rickets were due to calcium deficiency, vitamin D deficiency, or both, whereas osteoporosis was attributed to failure of new bone formation secondary to negative nitrogen balance, osteoblast insufficiency, or both. The rediscovery of earlier information that calcium deficiency led to the development of osteoporosis (not rickets and osteomalacia) in experimental animals

Young, M.M. & Nordin, B.E.C. 1967.Effects of natural and artificial menopause on plasma and urinary calcium and phosphorus. Lancet, 2: 118-120.

Stepan, J.J., Posphichal, J., Presl, J. & Pacovsky, V. 1987. Bone loss and biochemical

indices of bone remodeling in surgically induced postmenopausal women. Bone 8: 279-284.

Kelly, P.J., Pocock, N.A., Sambrook, P.N. & Eisman, J.A. 1989. Age and menopause-related changes in indices of bone turnover. J. Clin. Endocrinol. Metab., 69: 1160-1165.

Christiansen, C., Christensen, M.S., Larsen, N-E. & Transbøl, I.B. 1982. Pathophysiological mechanisms of estrogen effect on bone metabolism. Dose-response relationships in early postmenopausal women. J. Clin. Endocrinol. Metab., 55: 1124-1130. 

resulted in a reexamination of osteoporosis in humans, notably in postmenopausal women. This re-examination yielded evidence in the late 1960s that menopausal bone loss was not due to a decrease in bone formation but rather to an increase in bone resorption,

Parfitt, A.M. 1990. Osteomalacia and related disorders. In: Metabolic Bone Disease and Clinically Related Disorders. Second Edition. Avioli, L.V., Krane, S.M., eds. p. 329-396. Philadelphia: W.B. Saunders,

and this has had a profound effect on our understanding of other forms of osteoporosis. Although reduced bone formation may aggravate the bone loss process in elderly people

Need, A.G. Corticosteroid hormones. In: Metabolic Bone and Stone Disease. Third Edition. Nordin, B.E.C., Need, A.G., Morris, H.A., eds. p.70-78. Edinburgh: Churchill Livingstone.

and probably plays a major role in corticosteroid osteoporosis–

Horowitz, M. 1993. Osteoporosis in men. In: Metabolic Bone and Stone Disease. Third Edition. Nordin, B.E.C., Need, A.G., Morris, H.A., eds. Edinburgh: Churchill Livingstone, 

and possibly in osteoporosis in men 

Lips, P., Netelenbos, J.C. & Jongen, M.J.M. 1982. Histomorphometric profile and vitamin D status in patients with femoral neck fracture. Metab. Bone Dis. Relat. Res., 4: 85-93.

– bone resorption is increasingly held responsible for osteoporosis in women and for the bone deficit associated with hip fractures in elderly people of both sexes.

Truswell, S. 1983. Recommended dietary intakes around the world. Report by Committee 1/5 of the International Union of Nutritional Sciences. Nutr. Abstracts Revs., 53: 939-1119.

Because bone resorption is also the mechanism whereby calcium deficiency destroys bone, it is hardly surprising that the role of calcium in the pathogenesis of osteoporosis has received increasing attention and that recommended calcium intakes have risen steadily in the past 35 years from the nadir which followed the publication of the report from Rome in 1962. 

The process has been accelerated by the growing realisation that insensible losses of calcium (via skin, hair, nails, etc.) need to be taken into account in the calculation of calcium requirement.

Food and Nutrition Board, Institute of Medicine. 1997. Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington DC: National Academy Press.

As the calcium allowances recommended for developed nations have been rising – and may still not have reached their peak – the gap between them and the actual calcium intakes in developing countries has widened. The concept that calcium requirement may itself vary from culture to culture for dietary, genetic, lifestyle, and geographical reasons is emerging. This report therefore seeks to make it clear that our main recommendations – like the latest recommendations from USA and Canada,

Department of Health. 1991. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report of the Panel on Dietary Reference Values of the Committee on Medical Aspects of Food Policy. London: HMSO.

Great Britain,

Directorate-General Industry. 1993. Reports of the Scientific Committee for Food (Thirty-first series). Nutrient and energy intakes for the European Community. Luxembourg: Office for Official Publications of the European Communities.

the European Union,

National Health and Medical Research Council. 1991. Recommended Dietary Intakes for use in Australia. Canberra: Commonwealth of Australia.

and Australia –

are largely based on data derived from the developed world and are not necessarily applicable to nations with different dietary cultures, different lifestyles, and different environments for which different calculations may be indicated.