What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
Can you take vitamin D and magnesium together?
Tested together, with split results.
As of August 2026, vitamin D and magnesium have been tested together in 2 trials, in adults with a history of bowel polyps and overweight adults, and the results split between helped and no effect. Scored under the same rules as everything here.
30 studies · 2 tested the actual pair
What you’re seeing
- Vitamin D renders hollow: for bone, it is well studied and it does not work.
- Magnesium renders half-there: for sleep, the science is still forming.
- The woven cord is the rare part: two trials gave both together, and the results split between helped and no effect.
You can tell before you read a word.
Magnesium + L-theanine are sold together in the same aisle. No trial has ever tested the pair. When that is true, we draw nothing between them. The nothing is the review.
The two pair trials
- 2018Randomized trial · 180 people · adults with a history of bowel polyps · the pair helpedsource
- 2023Randomized trial · 78 people · overweight adults · no clear effectsource
The other 28 studies on file tested each one alone. See all 30 studies
Fair questions
Is it safe to take vitamin D and magnesium together?+
The studies on this page gave both together and reported no harm from the combination. That is not the same as a safety trial, and it says nothing about your dose or your medication.
How many studies is this based on?+
2 that gave the pair together. The papers are listed above with links to the source.
Deeper
What each one is on its own+
Vitamin D
- Bonehollow
- Blood sugarsolid
- Pregnancyhalf-there
Magnesium
- Sleephalf-there
- Blood pressuresolid
- Blood sugarsolid
- Cholesterolhalf-there
- Hearthalf-there
- Moodhalf-there
- Stress and anxietyhalf-there
- Weight and body fathalf-there
Pairs that have been tested+
- Vitamin D has been tested with selenium, folate, chromium, probiotics, omega-3, iron.
- Magnesium has been tested with melatonin, L-carnitine, probiotics, potassium, calcium, vitamin E.
These are the combinations someone has actually run a study on. Every other pairing here is air.