Vitamin D and B12: can you take them together?

Yes, vitamin D3 and vitamin B12 can be taken together. They are different vitamins that do not compete for the same absorption route, and the NIH Office of Dietary Supplements' vitamin D fact sheet lists no interaction with B12. We cite no trial of the pair. What matters is the vitamin D total against the 100 mcg (4,000 IU) limit.

Why the two are usually fine together

Vitamin D is fat-soluble: it dissolves in oil and is absorbed with dietary fat. Vitamin B12 is water-soluble and has its own absorption route. Because they are handled differently, there is no reason to separate them by hours, and no study we cite suggests you should. The medicines and nutrients that NIH ODS names as interacting with vitamin D are orlistat, certain statins, steroids such as prednisone and thiazide diuretics; B12 is not among them. Check that fact sheet for current wording, and ask a pharmacist about your own medicines.

What we do not have is a trial of the pair. We cite no study that measures absorption of D3 and B12 together against each apart, and none that tests a health outcome with the two combined. So the answer "yes, you can" rests on how the vitamins are absorbed and on the absence of a listed interaction, not on a combined trial, and we make no claim about what the pair does.

When to take them

With a meal that contains some fat. In a trial of 50 healthy older adults, a single 50,000 IU dose of vitamin D3 reached a peak blood level 32% higher (95% CI 11% to 52%) after a fat-containing breakfast than a fat-free one. B12 does not need the fat, but it does no harm there, so one habit can cover both. We found no trial of the best time of day for either. The timing detail is in when to take vitamin D.

Combined D3 and B12 products: count the vitamin D

Combined products exist, as capsules, gummies and sprays. The risk with any of them is the same one as with a single product: the vitamin D adds to whatever else you take. The adult upper limit is 100 mcg (4,000 IU) a day from food and supplements together. If the combined product is 25 mcg (1,000 IU) and you also take a 50 mcg (2,000 IU) softgel, you are at 75 mcg. B12 has no comparable limit in the NIH ODS tables, but check the amount on any label.

Our Personal Routines "D Complex" pill carries 125 mcg (5,000 IU) of vitamin D3 alone, over the limit, and must not be combined with our 50 mcg softgel or with any other vitamin D product. See how much vitamin D is too much for the numbers.

What we do and do not say about the pair

People search for "benefits" of the combination. We make no benefit claim for vitamin D3 at 2,000 IU: the large trials at that dose, in generally healthy adults over 50, found no effect on cancer or cardiovascular events (VITAL, 25,871 adults, median 5.3 years). We cite no trial of vitamin B12 with it. The research on what vitamin D does and does not show is in vitamin D benefits.

Our softgel

Electric Tiger Vitamin D3 is a single-nutrient softgel: 50 mcg (2,000 IU) of vitamin D3 as cholecalciferol, with no B12 and no other vitamin in it, as low as $15.35 a bottle on subscription. If you take a separate B12, the two do not overlap in what they contain.

Questions people ask

Can you take vitamin D3 and B12 together, or B12 and D3 together?

Yes. They are absorbed differently, and no interaction is listed in the NIH ODS vitamin D fact sheet. We cite no trial of the combination.

What is the best time to take vitamin D3 and B12?

With a meal that has some fat, at a time you will repeat daily. We found no trial that compares morning with evening for either.

Are vitamin D3 and B12 gummies or K2 combinations different?

The vitamins are the same; the format and the amounts differ, so read the vitamin D line and add it to your total. We cite no trial of D3 with B12 or K2.