Short answer

We found no documented interaction between Carnitine and Vitamin D3 with A, E and K2 in the sources below. That isn't proof the combination is right for you: check each one's cautions, and ask your pharmacist if you take medication.

Carnitine

What it is: A nutrient the body makes and gets from meat; it helps turn food into energy.

What the research says: Healthy people make all they need. Results for dementia and other conditions are mixed.

Cautions

• 3 g a day or more can cause nausea, cramps, diarrhea and a fishy body odor.
• High amounts may cause muscle weakness in kidney disease and raise seizure risk in people with seizure disorders.

Medicines to check

• Some anti-seizure medicines (phenobarbital, valproic acid) and long-term use of some antibiotics can lower carnitine levels

In Holitro: Carnitine (500 mg per capsule)

Source: NIH Office of Dietary Supplements: Carnitine: Fact Sheet for Consumers (updated May 2023)

Vitamin D3 with A, E and K2

What it is: A combination of vitamin D3 with vitamins A, E and K2. Vitamin D helps the body absorb calcium and supports muscles, nerves and the immune system.

What the research says: Getting enough vitamin D and calcium helps protect against osteoporosis.

Cautions

• Adults shouldn't exceed 4,000 IU (100 mcg) of vitamin D a day from all sources unless a clinician advises more. Too much can cause nausea, weakness, confusion and kidney stones.
• Too much preformed vitamin A can cause headaches and blurred vision, and birth defects in pregnancy.
• High-dose vitamin E supplements may raise bleeding risk.

Medicines to check

• Warfarin: vitamin K and vitamin E both matter, and vitamin K intake should stay steady
• Statins, steroids, orlistat and thiazide diuretics (vitamin D notes)
• Vitamin A-based medicines such as acitretin

In Holitro: D Complex (5,000 IU per capsule)

Sources: NIH Office of Dietary Supplements: Vitamin D: Fact Sheet for Consumers (updated November 2022); NIH Office of Dietary Supplements: Vitamin A: Fact Sheet for Consumers (updated March 2025); NIH Office of Dietary Supplements: Vitamin E: Fact Sheet for Consumers (updated March 2021); NIH Office of Dietary Supplements: Vitamin K: Fact Sheet for Consumers (updated March 2021)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.