Can You Take Fish Oil With a Multivitamin?

Quick answer

No source we read says fish oil and a multivitamin clash, and they supply different things: vitamins and minerals from the multi, EPA and DHA from the oil. The one pattern with data is a meal that has some fat, which in one trial raised absorption of EPA from 69% to 90%. Both touch warfarin, from opposite sides.^1,2,3

Key facts

A multivitamin supplies vitamins and minerals while fish oil supplies the omega-3 fats EPA and DHA, so they overlap only if the oil is cod liver oil, which also carries vitamins A and D.^4,5
Taking fish oil with a high-fat meal instead of a low-fat one raised EPA absorption from 69% to 90% for ordinary fish oil, and roughly tripled it for ethyl esters.¹
Vitamin D is fat soluble and is best absorbed with a meal or snack that includes some fat.⁶
Vitamin K in a multi works against warfarin, while high doses of omega-3 might lengthen clotting time in people who take it.^3,7
No upper limit is set for EPA and DHA, and FDA's advice is to keep supplements to 5 g a day or less.^3,8

Two supplements with little in common

The three main omega-3s are ALA, found mainly in plant oils, and EPA and DHA, found in fish and other seafood.⁸

Labels show each nutrient as a percentage of its Daily Value (DV). The DV is often, but not always, close to the Recommended Dietary Allowance, the daily amount that covers the needs of nearly all (97 to 98%) healthy people.^2,4

Most of what a multi holds is a vitamin or a mineral, each counted against a Daily Value. Fish oil is a source of fat, and the quantity that matters is milligrams of EPA and DHA.^2,5

Cod liver oil supplies EPA and DHA plus vitamins A and D, in amounts that vary from product to product. Vitamins A and D can be harmful in excessive amounts.^3,5

How the evidence grades compare

Fish oil has one strong grade, for raising blood levels of EPA and DHA, and one moderate grade for a normal heart function that comes with a 250 mg condition. The multivitamin claim below is moderate and describes a B vitamin role, not a result from trials of multis as a whole.^9,10

Raises EPA and DHA levels in the blood*^3,9

Strong evidence

In a five-month randomized trial in 115 healthy adults, 600 mg a day of EPA plus DHA from standard fish oil raised the omega-3 index (the share of EPA and DHA in red blood cell membranes) by 59%, with no change on placebo. NIH notes that all the common forms of omega-3 supplement raise blood EPA and DHA. Typical US intake from food is only about 90 mg a day.

Amount studied: 300 to 1,800 mg of EPA plus DHA a day; the 59% rise was at 600 mg a day for about five months

Provides EPA and DHA, which contribute to normal heart function*^3,11,12

Moderate evidence

This is the nutrient-function statement authorized in the EU, on condition that the daily intake is at least 250 mg of EPA plus DHA. It rests mainly on studies linking fish and omega-3 intake with heart health. It is not a promise of fewer heart problems: in the 25,871-person VITAL trial, about 840 mg a day did not improve the trial's main heart outcome.

Amount studied: At least 250 mg of EPA plus DHA a day, the EU condition for this statement

Provides B vitamins that contribute to normal energy-yielding metabolism*^10,13

Moderate evidence

Thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, vitamin B12 and biotin are needed by the enzymes that release energy from food; niacin alone is part of a coenzyme used by more than 400 enzymes. 'Contributes to normal energy-yielding metabolism' is the wording European regulators permit for each of these vitamins, and this product supplies more than the Daily Value of each. It does not mean extra B vitamins give more energy to someone who already gets enough.

Amount studied: The recommended daily intake of each B vitamin, from food and supplements together

Why a meal with fat matters for both

In a study of male volunteers, taking fish oil with a high-fat meal (44 g of fat) instead of a low-fat one (8 g) raised absorption of EPA from ordinary fish oil from 69% to 90%, and roughly tripled absorption of EPA and DHA from fish oil ethyl esters, to about 60%.¹

During a period of low-fat eating, only 3 of 50 adults taking a single 4 g dose of an ethyl ester product absorbed even half as much EPA and DHA as they did during a period of high-fat eating.¹⁴

Vitamin D is fat soluble, so it is best absorbed with a meal or snack that includes some fat.⁶

Our two labels already point the same way. Men's Multi is directed as two capsules in the morning with a meal, and Omega-3 as one softgel twice a day with meals, so one softgel can go with the multi at breakfast and the second with a later meal.

Amounts, and the overlap to watch

What the sources give for omega-3, and what our label gives^3,8
	Amount of EPA plus DHA
Average US intake from food	About 90 mg a day
European reference amount for adults	250 mg a day
A typical fish oil softgel	About 300 mg (180 mg EPA, 120 mg DHA)
Our Omega-3 at two softgels a day	600 mg a day
Prescription omega-3, under a doctor's care	About 3.4 g a day
FDA's advice for supplements	5 g a day or less

Our Omega-3 is a fish oil concentrate and lists no vitamin A or D, so it adds none to what Men's Multi carries. A cod liver oil in its place would, which matters because vitamin A from preformed sources has a 3,000 mcg upper limit from all sources.^5,15

What's in ours

What’s in ours

Men's Multi: Vitamin A, 600 mcg RAE per serving, from the label

What’s in ours

Omega-3: Fish oil concentrate, 1,000 mg per serving, from the label

Cautions, medicines and who should ask first

Ask your pharmacist or doctor first

Vitamin K counters warfarin, and the warfarin label lists more vitamin K in the diet among the factors that weaken its effect. NIH says people who take warfarin should talk with their health care provider before taking any multivitamin that contains vitamin K.^4,7

On the medicine's label

Your doctor may want to check on you

High doses of omega-3s may cause bleeding problems when taken with warfarin or other anticoagulants, and fish oil can have antiplatelet effects at high doses. Fish oil might also prolong clotting time, measured as INR, in people taking warfarin. The label of a prescription omega-3 medicine says people who also take an anticoagulant or an antiplatelet medicine should be monitored periodically.^3,8,16

On the medicine's label

Doses of 2 to 15 g a day of EPA and DHA might lengthen bleeding time by making platelets less likely to clump.³

Two large trials found that 4 g a day for several years slightly raised the risk of atrial fibrillation, an irregular heart rhythm, in people with or at high risk of heart disease. Across seven large trials, the rise was larger above 1 g a day than at 1 g or less.^3,17

It is not known whether people allergic to fish or shellfish are more likely to react to a prescription omega-3 medicine made from fish oil. Its label advises caution in people with these allergies.¹⁶

If you take warfarin or another blood thinner, ask before starting either product. The two work from opposite directions: the multi's vitamin K lowers warfarin's effect, and high doses of omega-3 might lengthen clotting time.^4,8
Ask first about fish oil if you are allergic to fish or shellfish, have an irregular heart rhythm or a bleeding disorder, or have been prescribed omega-3 medicine, since a supplement is not a substitute.^16,17
Ask first about the multi if you take levothyroxine, an antibiotic, methotrexate or a seizure medicine, or if you smoke and the product has large amounts of beta-carotene or vitamin A.⁴

Questions people ask

Can you take fish oil and a multivitamin together?

No source we read says you cannot. They supply different things, and the one point of contact is warfarin, where the multi's vitamin K works against the drug and high doses of omega-3 might lengthen clotting time. Ask a prescriber first if you take a blood thinner, and add up the vitamin A if you use cod liver oil alongside a multi.^5,7,8

What is the best time to take a multivitamin and fish oil?

With a meal that includes some fat. Vitamin D is best absorbed that way, and a high-fat meal raised EPA absorption from fish oil from 69% to 90% in one trial. Our Men's Multi is directed in the morning with a meal, and our Omega-3 twice a day with meals.^1,6

Does fish oil add vitamins to a multivitamin?

A standard fish oil does not. Cod liver oil is the exception, because it supplies vitamins A and D in amounts that vary from product to product and can be harmful in excess. Our Omega-3 is a fish oil concentrate with no vitamin A or D listed.^3,5

Do I need fish oil if I take a multivitamin?

A multi does not supply EPA and DHA. US adults get about 90 mg a day from food, the European reference amount is 250 mg, and NCCIH notes that for some outcomes the evidence for eating seafood is stronger than for supplements.^3,5

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Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.