I have found some crew members are having stomach trouble.
Do not take vitamins in transparent gelatine capsules. The capsule melts in the upper stomach can give you what feels like a stomach ulcer – too full, burning, pain after eating.
This is because the vitamin powder is dumped by the capsule when it melts into the upper area instead of the lower intestine as it should be.
A coated tablet is the answer. It’s called "enteric (for intestine) coated".
There are "'enteric gelatine capsules"' made which dissolve an hour after being taken. You put vitamin powder in them.
To handle the "ulcer feeling" – pain or too full or burning – one takes 2 aluminum hydroxide tablets (one trade name is Maalox No. 2) (chewing them up) and a few swallows or a glass of milk every couple hours and in a day or two all should be back to normal – unless or course you continue to take harsh, fast dissolving pills!