From Evidence to Consumers

Where do the numbers on the bottle actually come from?

1,000 IU vitamin D. 18 mg iron. 400 mg magnesium. The numbers on supplement labels look precise and authoritative. Few people know where they come from, and the answer changes how you read every label.

From Evidence to Consumers follows nutrition science from the research literature to the supplement aisle. The translation happens in stages: from research to recommendations, from recommendations to product doses, from the label into the body, and from the evidence into marketing. At every step, something gets lost. This book shows what that is, and why it matters to the person holding the bottle.

Inside, you will find out:
• why the same 1,000 IU vitamin D capsule means something different in London, Boston and Berlin
• why recommended intakes were set for populations and say little about any one person
• why the dose on the label is not the dose the body absorbs, and how common medicines such as metformin and proton-pump inhibitors change the picture
• where micronutrients clearly matter, in pregnancy, older age, vegan diets and after bariatric surgery, and where the evidence runs thin
• how health claims are regulated, and how "contributes to normal energy metabolism" turns into "will give me more energy"
• how to judge product quality, from fish oil oxidation to adulterated products

The book ends with ten practical questions to ask before taking any supplement, a reader's charter for everyday nutrition information, and tables comparing reference values across countries.

It will not tell you what to take. It will help you ask better questions.

Written for informed consumers, pharmacists, physicians and dietitians, and for people working in the supplement industry and its regulation.

About the author
Dr Volker Spitzer has worked for almost four decades in micronutrient science, consumer health and regulation: as a professor of pharmaceutical sciences, in research and development at Roche, DSM Nutritional Products and Bayer Consumer Health, and at IQVIA. He has authored more than ninety publications.