Calcium nutrition and bone health in the elderly

Abstract

The average elderly person is in negative calcium balance and accordingly is losing bone mass. While factors such as decreased mechanical loading of the skeleton undoubtedly figure in this age-related loss, a growing body of evidence suggests that inadequate calcium intake may contribute to this loss. On any given day men and women in the US 65 yr or older ingest about 600 and 480 mg calcium, respectively. Calcium intake in the elderly is less than in the young, and reduced absorption efficiency further lowers effective intake. Additionally, other nutrients such as protein and fiber, taken in excess, effectively increase the calcium requirement. Estrogen withdrawal at menopause leads to a decrease in intestinal calcium absorption efficiency and in renal calcium conservation, both effects equivalent to an effective increase in calcium intake requirement. Thus it is not surprising that all studies of mean requirements for zero balance performed in elderly subjects have yielded values above the current RDA for the US. The available evidence thus suggests that the RDA for adults should surely not be lowered below its current level (800 mg), but that, instead, it ought to be raised. It is not possible to say with certainty to exactly what level, but available evidence is compatible with allowances of at least 1200 to 1500 mg/day. Further, the evidence indicates that the mean requirement ought to be thought of as a complex function of age, sex, absorption efficiency, intake of protein, fiber, and probably other nutrients, estrogen status, and mechanical loading. Extensive experience with calcium supplements indicates that daily intakes up to at least 2.5 g of elemental calcium are quite safe in all persons except for certain subsets of the population uncommon among the elderly (eg, those with sarcoidosis, active tuberculosis, or other absorptive hypercalciuric syndromes). At the same time it must be said that osteoporosis is a complex, multifactorial disorder, and that factors unrelated to calcium nutrition undoubtedly play important, even dominant roles in many--perhaps most--osteoporotics. The available evidence, taken together, does not indicate that raising calcium intake will abolish the problem of osteoporosis. It does indicate, however, that calcium nutrition is considerably more important in the genesis of osteoporosis than has been commonly thought for the past 35 yr. As our listing of "important issues" indicates, the full extent of that importance, in both pathogenesis and prophylaxis, remains to be elucidated.(ABSTRACT TRUNCATED AT 400 WORDS)

Nutrition, ageing and ill health

“…There is some speculation that age-related renal impairment decreases the renal hydroxylation of vitamin D, thereby decreasing the amount of active vitamin D available for Ca absorption (Heaney et al 1982). Many institutionalized and free-living elderly (up to 50 % in some studies) have inadequate vitamin D intake, and the possible causes for this include sunlight deprivation, decreased intake of diary products, lactose intolerance and malabsorption of fat-soluble vitamins (Hoffman, 1993).…”

“…Ca alone without oestrogens cannot fully ameliorate post-menopausal bone loss, but Ca supplementation of 1000 mg daily with exercise does slow bone loss (Prince et al 1991). Although Ca supplementation may be necessary for certain groups of elderly people, it may be harmful in patients with a history of Ca stones, primary hyperparathyroidism, sarcoidosis or renal hypercalcuria (Heaney et al 1982). Recently, a randomized doubleblind placebo-controlled trial of the effects of 3 years of dietary supplementation with Ca and vitamin D in 176 men and 213 women over 65 years of age reported that dietary Alzheimer's disease delayed by 50 % the combined end point of death, admission to an institution, inability to perform the activities of daily living, or severe dementia (Sano et al 1997) In another trial eighty-eight healthy people aged 65 years or older were randomized to receive a-tocopherol (mg/d; 40, 130 or 430) or placebo.…”

Avaliação do estado nutricional e do consumo alimentar de mulheres no climatério

“…Consoante Hill et al 5 , a gordura proveniente da dieta é considerada determinante primária de obesidade, sendo esta mais prevalente em mulheres a partir do climatério 6 . Outros estudos revelam deficiência de nutrientes, como as vitaminas A e C 4,7 , o cál-cio 2,[8][9][10] e o ferro 4 .…”

Effect of Probiotic Dietary Intervention on Calcium and Haematological Parameters in Geriatrics

“…During ageing process, it has been reported that adequate calcium intake maintain the bone growth and avert bone loss. There have been growing evidence reporting that inadequate calcium intake may put in calcium loss because of decreased mechanical loading of the skeleton because of ageing [3].…”