Can I take magnesium or creatine with other supplements?

"Can I take these together?" is usually a timing question the label does not answer. For the pairs below, we looked for trials. Where a trial exists, it is described. Where we did not find one, the page says so. A missing trial is not the same as a ban, and it is not permission either.

Magnesium with vitamin D

This is the pair with a direct trial. Cheung 2022 (PMID 35576873) randomized 95 adults with overweight or obesity to magnesium plus vitamin D, vitamin D alone, or placebo for 12 weeks. The combined arm is described as 360 mg magnesium glycinate plus 1000 IU vitamin D3 daily. That group had the largest rise in 25-hydroxyvitamin D, 6.3 ± 8.36 ng/mL. Systolic blood pressure fell by 7.5 ± 8.26 mmHg only in combined-arm participants whose starting systolic pressure was above 132 mmHg. Parathyroid hormone and inflammation markers did not change. The authors say the combination may raise vitamin D status more than vitamin D alone in this group.

Dall 2023 (PMID 36640582) is the same dose, from the same research group (360 mg magnesium glycinate and 1000 IU vitamin D3; NCT03134417). Seventy-eight people finished. Vitamin D was higher than placebo. Osteocalcin, glucose, insulin, adiponectin, and HOMA-IR were not different between groups. So the combination can move the vitamin D blood test. In this 12-week window it did not move bone-turnover or blood-sugar markers.

These are not two independent replications. Treat them as one program reported twice. They also do not say you must swallow the capsules at the same minute. They tested a daily combination, not a clock time.

Magnesium with iron, zinc, or calcium

We did not read a randomized trial that settles whether magnesium glycinate must be separated from iron, zinc, or calcium. Internet charts often invent a two-hour gap. That gap is not a result in the papers above. If you take iron for a diagnosed deficiency, follow the instructions that came with that prescription or supplement, and do not stack a new mineral plan on top without the clinician who is checking your levels.

Creatine with collagen

We did not read a trial of creatine plus collagen against creatine alone. They are not substitutes. The comparison is on collagen vs creatine. Taking them the same day is not forbidden by anything we read. It is also not a proven stack.

Creatine with protein

Training studies of creatine are done in people who eat, and often in people who lift. That is not a trial of "creatine must go in the whey shake." Jacinto 2022 (PMID 35042187) compared 35 g whey with 35 g leucine-matched collagen in 22 untrained young adults over 10 weeks of lifting. Whey increased muscle thickness more. Strength and power rose similarly. Impey 2018 (PMID 29757056) gave 8 men whey or a collagen blend around a single ride and found a bigger leucine and p70S6K1 signal from whey. Neither study dosed creatine.

The postmenopausal creatine review found its lean-mass and leg-press gains when creatine was at least 5 g/day plus resistance training (PMID 42141930). Protein was not the variable they isolated. If you use both, the evidence we have is for each product's own outcome, not for a special combined timing.

Creatine with pre-workout

We did not read a trial showing that a stimulant pre-workout changes what creatine does. Many pre-workouts already list creatine, sometimes well under 5 g, buried in a blend. If the label does not state a creatine dose you can add up, you do not know whether you are taking the dose used in the trials. Caffeine and other stimulants are a separate decision, with their own sleep and blood-pressure issues, and this page is not a review of those trials.

Questions people ask

Can I take magnesium with vitamin D?

A 12-week trial in adults with overweight or obesity found 360 mg magnesium glycinate plus 1000 IU vitamin D3 raised 25-hydroxyvitamin D more than the other arms. A report from the same program found no change in bone-turnover or blood-sugar markers. Nothing we read requires they be taken at the same minute.

Can I take magnesium with iron, zinc, or calcium?

We did not find a trial that proves you must separate magnesium glycinate from iron, zinc, or calcium. Do not treat a two-hour rule from a chart as a study result. If iron was prescribed, follow that advice.

Can I take creatine with collagen, protein, or pre-workout?

We did not find a trial that says these must be taken together or must be kept apart. Whey beat collagen for muscle thickness in one 10-week trial that did not use creatine. Pre-workout labels often hide a creatine dose below the 5 g used in the positive postmenopausal trials. Read the gram amount.