Positive correlation between dietary intake of sodium, and balances of calcium and magnesium in young Japanese adults -Low sodium intake is a risk factor for loss of calcium and magnesium

• Published in: Journal of Nutritional Science and Vitaminology 2005, Vol.51(4), pp.265-270
• Main Authors: Nishimuta, M.(Incorporated Administrative Agency of Health and Nutrition, Tokyo (Japan)), Kodama, N, Morikuni, E, Yoshioka, Y.H, Matsuzaki, N, Takeyama, H, Yamada, H, Kitajima, H
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; CALCIO; CALCIUM; Calcium - analysis; Calcium - metabolism; calcium balance; Diet; Diet, Sodium-Restricted - adverse effects; estimated average; Feeding. Feeding behavior; Female; FISIOLOGIA HUMANA; FOOD INTAKE; Fundamental and applied biological sciences. Psychology; human; HUMAN PHYSIOLOGY; Humans; INGESTION DE ALIMENTOS; JAPAN; JAPON; MAGNESIO; MAGNESIUM; Magnesium - analysis; Magnesium - metabolism; magnesium balance; Male; Nutritional Requirements; PHYSIOLOGIE HUMAINE; PRISE ALIMENTAIRE (HOMME); Regression Analysis; Risk Factors; SODIO; SODIUM; sodium intake; sodium requirement; Sodium, Dietary - administration & dosage; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0301-4800; 1881-7742
• DOI: 10.3177/jnsv.51.265

The content of calcium (Ca) and magnesium (Mg) in sweat during exercise is considerably higher during a relatively low intake of sodium (Na) of 100 mmol/d than with an intake of 170 mmol/d. For this reason and also because Ca and Mg have a negative balance with a Na intake of 100 mmol/d, we analyzed the relationship between Na intake and balances of Ca and Mg in data from 11 balance studies. From 1986 to 2000, 109 volunteers (23 males, 86 females) with an age range of 18 to 28 y took part in mineral balance studies. The balance periods ranged from 5 to 12 d. In a given experiment, the diet of each subject contained the same quantity of food, although this varied between experiments, and was supplied during the balance period without consideration of body weight. In the data of all the studies (n=109), the balances of Ca and Mg did not correlate positively with Na intake. However, when the data of the highest Na study were excluded, the balances of Ca and Mg correlated positively with Na Intake. The mean value for the regression equation between Na intake and Ca and Mg balances when the respective balance was equal to zero were, 63.308 mg Na/kg BW/d (Ca: n=96, r(2)=0.134) and 60.977 mg Na/kg BW/d (Mg: n=96, r(2)= 0.268), respectively. These values are considerably higher than Na requirements estimated by inevitable Na loss. Low dietary Na may therefore be a risk factor for maintaining positive balances of Ca and Mg.