Can I take D Complex with Melatonin SR?

Understanding the interactions, benefits, and safety of combining these two powerful supplements.

D Complex
+
Melatonin SR

Short answer

We found no direct interaction between Vitamin D3 with A, E and K2 and Melatonin in the sources below, but they share a caution.

Both have a note about blood thinners such as warfarin (see each one below).

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)

Melatonin (slow release)

What it is: A slow-release form of melatonin, the hormone the brain makes in the dark to set your sleep-wake clock.

What the research says: Melatonin may help with jet lag and some circadian sleep problems. Sleep-medicine guidelines say there isn't enough evidence to recommend it for chronic insomnia.

Cautions

  • Short-term use seems safe for most people; long-term safety isn't known.
  • Older adults may feel drowsy the next day.

Medicines to check

  • Blood thinners and epilepsy: use only under medical supervision

Source: NIH National Center for Complementary and Integrative Health: Melatonin: What You Need To Know (updated May 2024)

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.

Stop Guessing Your Dosages.

Balancing dosages across multiple different bottles is risky, inefficient, and expensive. D Complex is already lab-dosed in our Immune Pack, and Melatonin SR is in our Sleep Pack — either way, that’s one less bottle to manage.

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