Guides

Every statement tied to a primary source, with its evidence level shown.

• Calcium: the supplement question that experts still disagree about
• Choline: the nutrient almost nobody meets, and almost nobody discusses
• Copper: the mineral most people only hear about when zinc goes wrong
• Fibre: the one nutrient almost everyone is short of, and the numbers behind it
• Folate and folic acid: the clearest success in nutrition policy, and its one side effect
• Iron: why the number on the label is not the number your body gets
• Magnesium: widely under-eaten, and widely over-promised
• Niacin: the vitamin that became a heart drug and then failed the trials
• Phosphorus: almost nobody is short of it, and the real question is your kidneys
• Potassium: the mineral most people under-eat, and the one some people must limit
• Protein: who genuinely needs more of it, and what the extra does not do
• Riboflavin: a milk and egg vitamin, and what the migraine trials really show
• Selenium: a deficiency that kills and a supplement that does not help
• Sodium: what lowering it actually does to blood pressure and to death rates
• Thiamin: a deficiency that is mostly about alcohol, not about diet
• Vitamin A: the supplement that increased cancer in a randomised trial
• Vitamin B12: who actually needs to worry, and why the damage can be permanent
• Vitamin B6: a water-soluble vitamin that can still damage nerves permanently
• Vitamin C: what it does, how much you need, and what it will not do
• Vitamin D: what supplements do for bones, and what large trials found they do not do
• Vitamin E: the antioxidant that failed its trials and then caused harm
• Vitamin K: the nutrient whose most useful fact is about a medicine
• Zinc: the cold remedy that partly works, and the supplement that backfires