Which vitamin does skin make when exposed to sunlight?
AnswerVitamin D
UVB light lets skin make vitamin D from a cholesterol-based compound.
Health · Facts & stats
Diet facts & stats
7 fact-checked facts about diet and nutrients, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What does a food calorie (kilocalorie) measure?
AnswerEnergy
A kilocalorie is a unit of energy, the heat needed to warm 1 kg of water by 1°C.
Going deeper
Proteins are made of chains of what?
AnswerAmino acids
Proteins are long chains of amino acids folded into specific shapes.
The word 'diet' comes from the Greek 'diaita', meaning what?
AnswerWay of life
Diaita meant a way of living, which later narrowed to mean what a person eats.
Iron is a key part of which molecule that carries oxygen in blood?
AnswerHemoglobin
Each hemoglobin molecule holds iron atoms that bind oxygen.
Expert level
Lactose, the sugar in milk, is made of glucose joined to which sugar?
AnswerGalactose
Lactose is a disaccharide of glucose and galactose.
Which enzyme in saliva starts breaking down starch?
AnswerAmylase
Salivary amylase begins splitting starch into sugars while you chew.
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