Magnesium and zinc status in patients with chronic renal failure: influence of a nutritional intervention Cristina Sánchez 1 , Pilar Aranda 1 , Antonio Pérez de la Cruz 2 , Juan Llopis 1 1 Institute of Nutrition and Food Technology and Department of Physiology, School of Pharmacy, Cartuja Campus, University of Granada; 2 Servicio de Nutrición y Dietética, Hospital Universitario Virgen de las Nieves, Granada, Spain Correspondence: J. Llopis, Departamento de Fisiología, Facultad de Farmacia, Campus Cartuja, Universidad de Granada, 18071 Granada, Spain <jllopis@ugr.es> Abstract. Chronic renal failure (CRF) alters the metabolism for a number of ele- ments, and can lead to deficiency of these nutrients. Among the causes of these alterations are reduced food intake and the low element content of some low- protein diets recommended in CRF. This study aimed to determine whether nutri- tional status for magnesium and zinc were changed by a nutritional intervention providing patients with CRF with enough information to prepare a low protein diet that met their needs. The effects of the intervention were compared in 40 adult par- ticipants divided into two groups. The control group consumed their usual pre- scribed diet, and the nutritionally instructed group received dietary training to teach them how to choose foods that met their nutritional needs. The study period lasted 12 months. Food consumption was assessed by 24-h recall. Magnesium and zinc were measured in plasma at the start and at the end of the study. Participants in the nutritionally instructed group decreased their protein intake and increased that of carbohydrates, magnesium and zinc. Plasma zinc correlated with glomerular filtration rate, measured as creatinine clearance, (r = 0.37) plasma protein (r = 0.39) and zinc intake (r = 0.63). At the start of the study 1 participant in the control group and no participants in the instructed group had hypomagnesaemia (< 1.8 mg/dL) whereas 2 participants in the control group, and 5 in the instructed group had hypo- zincaemia (Zn < 70 μg/dL). After the intervention we observed no changes in the number of participants with hypomagnesaemia in either group, whereas hypozin- caemia was found in only 1 participant in the control group and 1 in the instructed group (changes in the instructed group were significant; p < 0.05). Nutritional inter- vention benefited our participants by improving their ability to choose foods that provided magnesium and zinc while reducing their protein intake. The results of this study indicate that the dietary intervention enabled participants to better con- trol their protein intake and zinc status without detriment to magnesium status. Key words: chronic renal failure, magnesium, zinc, nutritional status, nutritional intervention Chronic renal failure (CRF) provokes imbal- ances of elemental status in physiological fluids and tissues [1], and can lead to deficiency in or raised levels of these nutrients, but the mechan- isms responsible for these changes are poorly understood, and the contribution of toxicity or deficiency in some elements to the symptoms of CRF is uncertain. Among the causes of these alterations are reduced food intake and the low element content of some low-protein diets recom- mended in CRF to delay the progression of kidney damage [2, 3]. doi: 10.1684/mrh.2009.0170 Magnesium Research 2009; 22 (2): 72-80 ORIGINAL ARTICLE 72 Copyright © 2017 John Libbey Eurotext. Téléchargé par un robot venant de 54.191.40.80 le 28/06/2017.