Eli5: Why do vitamins mg not match their true weights?
In: Chemistry
What do you mean? That the tablet is heavier than the weight of vitamin it contains? If so it’s usually because of binders to make it hold together and other ingredients to make a useful tablet or capsule. If the dose is very small it needs bulking up to make it into something you can handle and swallow.
Do you mean why are vitamin tablets heavier than the sum of the individual vitamin weights on the label? It’s because there will be other ingredients known as excipients which are used to fill out the tablet to a suitable size and ensure it breaks up when it’s swallowed. As these aren’t active, they aren’t laid out in detail on the label.
Yes that is what I meant. I had figured it was something of that nature.
All pills and victim is have binders (inactive ingredients) to give them shape and size and meter out the dissolution/absorption. You can’t just press a bunch of vitamin and minerals together to get a pill — you need things like corn starch, calcium carbonate.
Be careful of things like salt forms, for example something like iron (not a vitamin, but close enough) can be present as iron gluconate in a supplement.
1 mole of iron gluconate weighs 446.1 grams, but only contains 55.8 grams of iron.
If you get vitamin C as sodium ascorbate, it will only contain ~89% ascorbic acid by weight due to the presence of sodium.
So you have to account for that difference when weighing it out for a supplement.
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