Hidden sodium in effervescent-tablet dietary supplements and over-the-counter drugs: a comparative cross-sectional study.

Dietary sodium intake represents a risk factor for cardiovascular disease and mortality. The study sought to analyse the sodium content of effervescent dietary supplements and drugs in Germany and the USA. Comparative cross-sectional study. The sodium content of 39 dietary supplement effervescent tablets available in Germany was measured in May and June 2022 using optical emission spectrometry with inductively coupled argon plasma. The sodium content of 33 common pharmacy-only effervescent tablets (over-the-counter (OTC) drugs) in Germany was obtained from the summary of product characteristics. We compared the sodium content of the measured German dietary supplement effervescent tablets to that of 51 dietary supplement effervescent tablets available in the USA (data: National Institutes of Health's Dietary Supplement Label Database). The measured sodium content in the German dietary supplements was 283.9±122.6 mg sodium/tablet, equivalent to 14±6% of the maximum recommended daily sodium intake (MRDSI). Vitamin products had the highest (378.3±112.8 mg, 19±6% of MRDSI), and calcium products had the lowest mean sodium content (170.4±113.2 mg, 9±6% of MRDSI). Vitamin products contained significantly more sodium than magnesium (378.3 mg vs 232.7 mg; p=0.004), calcium (378.3 mg vs 170.4 mg; p=0.006) and mineral products (378.3 mg vs 191.6 mg; p=0.048). The sodium content measured in products available in Germany was higher when compared with the declared sodium content on the label of the products sold in the USA (283.9 mg vs 190.0 mg; p<0.001). The median summary of product characteristics-declared sodium content of a single dose of the German OTC drugs was 157.0 mg (IQR: 98.9-417.3 mg); pain/common cold drugs contained the most sodium (median: 452.1 mg; IQR: 351.3-474.0 mg). Effervescent tablets of nutritional supplements and OTC drugs contain high amounts of sodium, which often is not disclosed.

Informations de copyright

© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Déclaration de conflit d'intérêts

Competing interests: MB is supported by the Deutsche Forschungsgemeinschaft (German Research Foundation; TTR 219, project number 322900939) and reports personal fees from Abbott, Amgen, AstraZeneca, Bayer, Boehringer-Ingelheim, Cytokinetic, Edwards, Medtronic, Novartis, ReCor Medical, Servier and Vifor. FM is supported by Deutsche Gesellschaft für Kardiologie (DGK), Deutsche Forschungsgemeinschaft (SFB TRR219) and Deutsche Herzstiftung and has received scientific support and/or speaker honoraria from AstraZeneca, Bayer, Boehringer Ingelheim, Medtronic, Merck and ReCor Medical. LL has received speaker honoraria from ReCor Medical and Medtronic. CU has received lecture honoraria or consulting fees from Bayer, Bristol Myers Squibb, Medtronic and ReCor Medical. UL has received speaker honoraria from Amgen, Daiichi Sankyo, Novartis and Sanofi, all outside the submitted work. MS has received speaker honoraria from BMS, Daiichi Sankyo, DGK-Academy, Pfizer and Sanofi and consulting fees from CSL Vifor, MSD and Novartis, all outside the submitted work. FG is supported by German Foundation for Heart Research (Deutsche Herzstiftung) and has received speaker honoraria from AstraZeneca. The other authors do not have conflicts of interest.