VCVITAMINS/CHART

The Bottom Line

Yes, you can take Vitamin B1 (Thiamine) and Krill Oil together — they are safe to combine and do not interact. Here is what you need to know.

VERDICT

Vitamin B1 (Thiamine) and Krill Oil together are a safe combination. Thiamine is a water-soluble B vitamin while krill oil provides fat-soluble omega-3s and astaxanthin, so they do not compete for absorption or interfere with each other. You can take them together without any special timing or precautions.

Safe to combine Strong evidence
01 / MECHANISM

How They Interact

Thiamine (vitamin B1) is a water-soluble vitamin absorbed mainly in the proximal small intestine via active transport at low doses and passive diffusion at higher doses. Krill oil is a lipid-based supplement whose omega-3 fatty acids are incorporated into phospholipids and absorbed through the lymphatic system alongside dietary fats. Because these two nutrients use entirely different absorption routes and do not share transporters or metabolic enzymes, they do not compete with or block one another. There is no evidence that krill oil affects thiamine phosphorylation, cellular uptake, or renal excretion, nor does thiamine alter the digestion or bioavailability of krill oil. In practical terms, they can be taken in the same meal or at different times without any interaction.

02 / BEST PRACTICES

How To Take Them

If you are taking both supplements, a simple approach is to take thiamine first thing in the morning on an empty stomach, then take krill oil with lunch or dinner. This maximizes absorption of the water-soluble vitamin and ensures the fat-soluble omega-3s are carried with food. You do not need to space them apart, but if you notice any stomach discomfort, separate them by 1–2 hours. Both are typically taken once daily, and consistency matters more than timing. If you miss a dose, just take it with your next meal, unless it is almost time for the next dose — then doubling up is not recommended.

03 / FORM MATTERS

Form & Quality Differences

Thiamine is available as thiamine hydrochloride (water-soluble) and benfotiamine (a fat-soluble derivative); benfotiamine may actually be absorbed better with food, unlike regular thiamine which is best on an empty stomach. Krill oil is already bound to phospholipids, making its omega-3s more water-dispersible than those in fish oil, so it is well absorbed with or without food. Regardless of form, the lack of interaction between thiamine and krill oil remains unchanged.

04 / COMMON STACKS

Where This Pair Shows Up

Thiamine is commonly included in B-complex and energy support formulas, while krill oil appears in joint health and cardiovascular supplements, so they are frequently combined in a general daily wellness stack rather than in a single product.

Multivitamins Prenatals Performance Longevity
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Practical Tips

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Frequently Asked Questions

Who Should Be Careful Most adults can take thiamine and krill oil together without concern. If you take blood-thinning medication, note that krill oil can have a mild antiplatelet effect, so discuss this with your doctor. People with kidney disease or on dialysis should not exceed high-dose thiamine without medical supervision. Pregnant and breastfeeding women should stick to standard dietary doses of both supplements unless their healthcare provider recommends otherwise.
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Sources & Further Reading

  1. NIH ODS NIH Office of Dietary Supplements — Vitamin B1 (Thiamine) Fact Sheet
  2. NIH ODS NIH Office of Dietary Supplements — Omega-3 Fatty Acids Fact Sheet
  3. Examine.com Examine.com — Thiamine interaction page
  4. Examine.com Examine.com — Krill Oil interaction page

Reviewed by Caroline M. on April 15, 2026 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.

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The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.

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