When is it best to take a multi-vitamin?

I take a multi-vitamin most days, and I’m starting to wonder what the best time to take it is. And, by time I mean relating to meals. I’ve heard that some vitamins are fat-soluble while others are water-soluble, but which ones? If the vitamins you’re taking are fat-soluble I’d assume you’d want to take them after you eat a meal that contains some fat. But how long after? 5 minutes? An hour? Maybe during the meal would be the best time.

Anybody know?


This is just a partial answer, and it’s about iron. When I had too little iron in my blood to donate blood, I got a fact sheet about getting a better score. Caffeine, it said, curbs the absorption of iron. So, if you use caffeine only at breakfast, like I do, and your multivite has iron in it, it’s better to take it later in the day, when it will absorb better.

That’s all I got.

I don’t think it matters. Vitamins A,D,E,K are fat soluble, but your body will absorb them easily assuming you don’t have a malabsorption disease. The fact they are fat soluble means they stay in your body for a long time. Water soluble vitamins tend to be pissed away (except vitamin B12 which is metabolized by the liver IIRC).
If you eat a healthy diet, you may not need a multivitamin at all. Our nutrition professor used to become apopolectic at the inclusion of nickel in some vitamins – “Nickel? What the fuck do you do with nickel?”

Yeah, I’m constantly debating whether or not my diet is lacking enough to warrant taking a multi-vitamin, or if I’m actually just putting undue stress on the systems that need to handle the vitamins I’m putting in. I’d say I have a better diet than the average American (no fast food, no red meat), but it’s by no means perfect.

Anyway, if it doesn’t matter when I take them I suppose I’ll take them whenever I please.

Thanks for the help!

It’s a question I think about a lot–I am American, and I eat plenty of fruits and veggies, but when I tally things up on fitday.com, I am often a little short of several vitamins.

So should I take a multivitamin? Can it hurt me to take a multivitamin? Should I take one six days a week and have a day of rest? Should I take one only, like, two days a week?

Actually, there are some absorption problems with some of the minerals. Calcium is only absorbed in the presence of magnesium and activated vitamin D (not the vitamin D you get in the multivitamin: vitamin D that has already been processed twice in your body, by the liver and the kidney). Iron is only absorbed if it is in the Fe++ state and not the Fe+++ state (rust); therefore, it absorbs better in the presence of acid.

The best clue I have ever been given was from a nutritionist doc who told me to take the vitamin with the sort of food it’s normally found in. If you have a shot at absorbing the contents of the vitamin, rather than turning it into expensive feces, it’s best in the company of the sort of food you would expect to absorb the vitamin from. This was one of those “Duh!” moments that had me thumping my head. Those delicately specific transmitters in the intestinal lining cell membranes are tuned to pick up the vitamins and minerals in the presence of the sorts of food your ancestors got them from. Well, duh…

For which reason, not to disagree with Dr. Paprkia, you may well have a better shot at absorbing A, D, E, and K in the presence of fat. But very little fat is required: that’s why vitamin K supplements are enclosed in a couple of cc of vegetable oil. If I were having cereal with milk with my multivitamin in the morning, and I was particularly concerned with absorbing the calcium, I would make sure it was 1% milk and not nonfat. Unless I also had a piece of toast with a pat of butter. Don’t need much to have enough.

The problem with A, D, E, and K is that it is possible to absorb too much of them, whereas if you overdo it on C or B vitamins, you’ll piss them away. Nevertheless, you can get your body used to way-overdoing it levels of water-soluble vitamins. I remember reading a paper years ago (sorry, no cite) about an experiment feeding young men major megadoses of vitamin C for six weeks (part of the investigation into vitamin C and colds that followed Linus Pauling’s hysteria). By major megadoses I mean several grams a day. When the experiment stopped and they quit cold turkey, several of them promptly came down with scurvy. Fortunately the experimenters kept an eye on them and were able to prescribe a few grams a day of vitamin C, backing it down slowly to one gram and then half a gram and then no grams, and to report this unforeseen consequence in their paper.

All this begs the question of whether you really need the multivitamin. Your ancestors got by fine without it, and they produced you. If we really needed multivitamin supplementation to survive, we wouldn’t be here.

God, I am tired. I misspelled Dr. Paprika and forgot to bold him, and I described vitamin K as being in a couple of cc of vegetable oil when I meant E.

Maybe i need to thump my head a bit harder.

I swear I bolded him that time.

I make a lot of spelling mistakes when I am tired; despite being a very good speller in real life. I also tend to write “their” instead of “there” and this problem is worsened by the fact I rarely edit my posts. It’s nice that you spell my pseudonym correctly and bold my name, but it is hardly worth a head thump. Plenty of my patients probably think I’m a prkia.

Gabriela knows way more about this stuff than I do. But fat digestion takes a long time and I would still guess your body can absorb enough of the vitamin A,D,E,K in the absence of fat. Perhaps vitamin makers account for this automatically with the other stuff besides vitamins that makes up the pill. If you have worries, take the pill within an hour of eating and you’ll be fine. I still doubt it makes that much difference, though.

In addition to foods that promote absorbtion of vitamins some foods decrease it. I’ve always heard that there are oxalates in spinach that will absorb enough calcium to be a problem if you consume it at the same meal.

Iron is absorbed better if you consume it with protein (IIRC, it’s called the MPF factor - Meat, Protein, Fish).