Original article Dynamics of magnesium, copper, selenium and zinc serum concentrations for 2-year dietary intervention q Ofra Paz-Tal a, * , Ayala Canfi a, b , Rachel Marko a , Esther Katorza a , Zeev Karpas a , Dan Schwarzfuchs a , Iris Shai b , Einat K. Sheiner a a Nuclear Research Center, Negev, Department of Chemistry, P.O. Box 9001, Beer Sheva 84190, Israel b International Center for Health and Nutrition, Department of Epidemiology and Health system Evaluation, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105, Israel article info Article history: Received 28 June 2012 Received in revised form 15 April 2013 Accepted 15 April 2013 Keywords: Essential elements ICP-MS Low-fat diet Mediterranean diet Low-carbohydrate diet Diabetes-type-II abstract Background & aims: Essential elements levels in serum are related to nutritional habits. We studied the association of magnesium (Mg), copper (Cu), zinc (Zn) and selenium (Se) concentrations in serum, with 3-dietary regimes, during 24-months of intervention. Methods: A representative subgroup (n ¼ 231;age ¼ 52 years;body-mass-index ¼ 32.8 kg/m 2 ; 85% males) of the 2-year dietary-interventional-trial (DIRECT) who were randomized to low-fat, Mediterranean or low-carbohydrates diets, were followed for changes of the essential elements serum concentrations, using Inductively-coupled-plasma-mass-spectrometry (ICP-MS). Results: The essential elements serum concentrations significantly increased after 12-months of dietary intervention as follows: magnesium; 1.88  0.33 to 2.05  0.33 mg/dL; p within group ¼ 0.002, copper; 1109  182 to 1245  371 mg/L; p < 0.001, selenium; 148  37 to 173  45 mg/L; p < 0.001 with no significant changes of zinc from baseline levels (955  182 mg/L to 991  284 mg/L; p ¼ 0.755). After 24- months, only magnesium continued to increase to 2.19  0.30 mg/dL; p < 0.001, while copper (1086  333 mg/L; p ¼ 0.534) and selenium (150  42 mg/L; p ¼ 0.581) returned to their baseline values. Zinc levels remained similar (930  221 mg/L; p ¼ 0.122). The changes (delta concentrations) were similar across the three diet types, after 12-months [p between groups ¼ 0.274(Mg); 0.521(Cu); 0.521(Zn); 0.565(Se)] and 24-months [p ¼ 0.462(Mg); 0.786(Cu); 0.295(Zn); 0.715(Se)]. Physical activity changes expressed as increasing Metabolic Equivalent Task (MET), after 12 months, decreased serum concen- trations of zinc (b ¼0.245 p ¼ 0.006 and copper (b ¼0.250, p ¼ 0.006), as evaluated by multiple linear regression in the entire group adjusted to sex, age, diet group and weight-loss with the nutrients pro- teins, fibers, carbohydrates, fats intake changes as cofactors. Conclusions: Healthy dietary interventions significantly elevated the levels of magnesium over 2 years, while copper, and selenium serum concentrations increased within the first year only, similarly across the three diets. Increasing physical activity significantly decreased the serum concentrations of zinc and copper after 12-months. (ClinicalTrials.gov number, NCT00160108.) Ó 2013 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved. 1. Introduction Selected elements, although present in minute quantities, are vital for the human body. Magnesium (Mg) and the trace elements copper (Cu), zinc (Zn) and selenium (Se), are crucial for both physiological and biochemical functions, are indispensable for the maintenance of healthy life, growth and reproduction. 1 As all chemical elements, they must be obtained from external sources via food, drink or supplements intake. 1 In humans, magnesium [concentration of milligrams per deci- liter serum (mg/dL)] is essential for bone metabolism and nervous q Conference presentations: 1. O. Paz-Tal, Is there differential effect of type of weight-loss strategy on changes in trace mineral concentration: A randomized control trail, EuroAnalysis conference, Innsbruck, Austria, 6-10 September 2009 (lecture) 2. O. Paz-Tal, Changes in trace mineral in serum and food group intake, in a 3 diet - types , 2-year interventional trial, Bioavailability, Monterey, USA , 26-30 September 2010 (poster). * Corresponding author. Tel.: þ972 8 6568017, fax: þ972 8 6568686. E-mail address: ofrapt@walla.com (O. Paz-Tal). Contents lists available at SciVerse ScienceDirect e-SPEN Journal journal homepage: http://www.elsevier.com/locate/clnu 2212-8263/$36.00 Ó 2013 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.clnme.2013.04.001 e-SPEN Journal 8 (2013) e100ee107