Vitamin B12 supplements are especially important for vegans, so it makes sense to pay a bit of extra attention to when you’re consuming them. See my guide to the best vitamin B12 supplements if you need to find one.
Vitamins are either water-soluble or fat-soluble.
Fat-soluble vitamins absorb best alongside food (ideally with a decent amount of fat), while water-soluble vitamins have to dissolve in water in order to be absorbed.
Since vitamin B12 is a water-soluble vitamin, it should ideally be taken on an empty stomach, along with some water. This goes for all other B vitamins as well.
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When is the Optimal Time to Take Vitamin B12
Even though you don’t eat constantly throughout the day, you might have food in your stomach if you eat an early breakfast.
That’s why the best time to take vitamin B12 is right when you get up in the morning. It’s also a good time to drink a glass of water, since you’re likely a bit dehydrated.
Doctors typically recommend taking it at least 30 minutes before your meal to give it time to absorb.
If that’s not possible because you need to eat right away, try to wait a few hours after eating before taking your vitamin B12 if you’d like to maximize your absorption rate.
Water soluble vitamins tend to absorb best when taken with water, and without food.
What Happens if You Take B12 With Food?
Even if you take it with food, you’ll still absorb some, and the amount of B12 that you actually need to absorb from supplements is very low.
The RDA of B12 is only a few micrograms, and most supplements have over 1,000 micrograms per serving.
So if you’re really concerned about getting enough B12, like if you’re in the process of correcting an existing deficiency, have it on an empty stomach. Otherwise, you don’t need to worry about if you take B12 with or without food too much.
Even if the absorption of vitamin B12 is a bit lower when consumed along food, it’s not something to worry about since you need such a small amount of vitamin B12 per day.
How Much Vitamin B12 Do You Need?
According to the NIH, the recommended daily amount of vitamin B12 for anyone over the age of 14 is 2.4 mcg.
That is not a typo – 2.4 micrograms, which is equivalent to 0.0024 mg. It’s an incredibly small amount.
That’s why it doesn’t really matter if you’re eating B12 with food or not. Either way your body only needs to absorb a very small amount of it.
Adults need just 2.4 micrograms of vitamin B12 per day, which is an incredibly small amount.
What Happens If You Take Too Much Vitamin B12?
There’s no actual “upper intake” limit for vitamin B-12.
Since it’s a water-soluble vitamin, any excess is typically just flushed out and your body can handle a large amount of B12 safely.
Still, there still could be some risk of taking too much B12. There is some evidence that too much vitamin B12 can trigger acne. It’s possible that there are other potential side effects as well.
While there’s not a big concern about getting too much vitamin B12, there’s also no need to consume more than the RDA, and there could be potential side effects for those that consume very large doses.