The effect of dietary sodium on urinary calcium and potassium excretion in normotensive men with different calcium intakes

Abstract

On the basis of their usual calcium intake, 12 healthy normotensive male students were divided into a low and a high calcium group. Both groups were provided with complete diets containing the same calculated quantities, expressed per MJ, of protein, fat, carbohydrate, sodium, potassium, phosphorus, and calcium. After an initial period of two weeks during which all participants received an additional 100 mmol sodium daily, 6 participants received an additional 22 mmol sodium/day (low sodium), the other 6 participants 178 mmol sodium/day (high sodium). After two weeks the sodium regimes were crossed over for a subsequent two-week period. When the second week of the low sodium period is compared with the second week of the high sodium period, the increase in the calcium/creatinine ratio, expressed on molar basis, was 0.059 for the low and 0.053 for the high calcium group (p less than 0.05). The increase in the molar potassium/creatinine ratio was 0.65 for the low and 0.03 for the high calcium group (p less than 0.025). However, after correcting for the calcium intake the effect in the low calcium group was found to be greater (p less than 0.05). Sodium supplementation was found to have no effect on blood pressure, but mean systolic (p less than 0.10) and diastolic in the high calcium group were lower. This suggests that calcium may well play a role in the regulation of blood pressure.

A 7-week reduction in salt intake does not contribute to markers of bone metabolism in young healthy subjects

“…This is in agreement with other studies, indicating that there are differences in the metabolic responses to sodium between the young and the elderly (Breslau et al, 1985;Itoh et al, 1999). Although the association between sodium intake and bone resorption in young subjects has been found in several studies (Goulding, 1981;Goulding & Lim, 1983;Chan et al 1992;Itoh & Suyama, 1996;Jones et al, 1997), opposite findings also exist (Castenmiller et al, 1985;Ginty et al, 1998).…”

“…A commonly suggested strategy to diminish bone loss is to maintain positive calcium balance by consuming a diet containing adequate amounts of calcium and vitamin D. The positive relationship between urinary sodium and calcium excretion in humans has been established previously in both cross-sectional (Goulding, 1981;Law et al, 1988;Shortt et al, 1988;Chan et al, 1992;Matkovic et al, 1995;Dawson-Hughes et al, 1996;Itoh & Suyama, 1996;O'Brien et al, 1996;Jones et al, 1997) and experimental studies (Breslau et al, 1982;Goulding & Lim, 1983;Castenmiller et al, 1985;Law et al, 1988;McParland et al, 1989;Zarkadas et al, 1989;Chan et al, 1992;Evans et al, 1997). It could be hypothesised that sodium-induced urinary calcium loss decreases serum calcium concentration, which is compensated for increased excretion of parathyroid hormone (PTH) from the parathyroid glands (Evans et al, 1997).…”

“…Most of the trials on the effects of sodium on calcium and bone metabolism have been conducted in the setting of shift from a low-sodium (Breslau et al, 1982;Castenmiller et al, 1985;McParland et al, 1989;Chan et al, 1992;Evans et al, 1997;Lin et al, 2003) or normal-sodium (Goulding & Lim, 1983;Law et al, 1988;Zarkadas et al, 1989;Evans et al, 1997) to a high-sodium diet. To our knowledge, there is only one study in which the changes in urinary calcium excretion and bone resorption were observed after subjects had restricted their habitual salt intake (Need et al, 1991).…”

Données nouvelles sur la prévention nutritionnelle de l’ostéoporose

“…Ainsi, chaque gramme supplémentaire de Na + consommé entraîne la fuite de 40 à 60 mg de calcium [8], ce qui induirait une perte osseuse additionnelle de 1 % si la totalité du calcium urinaire provenait du squelette. Ces données sont validées chez la femme ménopausée [9] et chez l'homme [10]. À l'inverse, une étude de cas a permis d'obtenir une réduction de l'excrétion urinaire de calcium (de 800 à 113 mg/j) après diminution de la consommation sodée associée à une prescription de 1g/j de calcium [11].…”

Consumo alimentar de beneficiários do programa Bolsa Família

“…FISBERG et al, 2013). O sódio, por sua vez, ingerido em elevadas quantidades pode aumentar a excreção urinária de cálcio (CASTENMILLER et al, 1985;BLAUSTEIN;LEDERER, 1999).…”