Magnesium needed for vitamin D activation
Magnesium is required for vitamin D metabolism. Low magnesium can impair vitamin D effectiveness.
Ensure adequate magnesium when supplementing vitamin D.
Can take together
Magnesium needed for vitamin D activation. Ensure adequate magnesium when supplementing vitamin D.
Can take together
This interaction is rated “Synergy” by Formulate. Magnesium is required for vitamin D metabolism. Low magnesium can impair vitamin D effectiveness.
Studies from our registry that mention magnesium or vitamin d. Each links to the primary source and the other Formulate pages citing it.
Mentions vitamin d · 2022
The D-Health Trial: a randomised controlled trial of the effect of vitamin D on mortality
Neale et al. · The Lancet Diabetes & Endocrinology
D-HEALTH trial (n=21,315). Monthly 60,000 IU vitamin D did not reduce all-cause mortality over 5 years.
Mentions vitamin d · 2019
Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease
Manson et al. · New England Journal of Medicine
VITAL trial (n=25,871). 2,000 IU/day D3 did not significantly reduce cancer incidence or cardiovascular events in a generally replete population.
Mentions magnesium · 2018
Superiority of magnesium and vitamin B6 over magnesium alone on severe stress in healthy adults with low magnesemia
Pouteau et al. · PLOS ONE
Mg+B6 combination outperformed Mg alone for stress score reduction in adults with low baseline magnesium.
Mentions magnesium · 2018
The role of magnesium in neurological disorders
Kirkland AE, Sarlo GL, Holton KF · Nutrients
Reviews mechanisms and clinical evidence for magnesium's role in migraine prophylaxis, stress, anxiety, and depression — with strongest RCT support for migraine prevention at 400–600mg/day.
Mentions vitamin d · 2017
Monthly High-Dose Vitamin D Supplementation and Cardiovascular Disease (ViDA)
Scragg et al. · JAMA Cardiology
ViDA trial (n=5,110). Monthly high-dose vitamin D did not reduce cardiovascular events.
Mentions vitamin d · 2017
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Martineau AR, Jolliffe DA, Hooper RL, et al. · BMJ
Individual-participant meta-analysis of 25 RCTs (n=10,933) found vitamin D supplementation reduced risk of acute respiratory tract infection, with greatest benefit in baseline-deficient participants and daily/weekly (not bolus) dosing.
Guide
Magnesium Glycinate vs Citrate vs Oxide: Which Form Actually Absorbs?
Glycinate (80% absorbed) vs citrate (50%) vs oxide (4%) — with elemental-dose math, side effects, and picks for sleep, constipation, and cognition.
Roundup
Best Magnesium Supplements 2026, Ranked by Clinical Evidence
Learn which magnesium form actually matches your goal. We scored glycinate, threonate, and citrate on absorption, dose accuracy, and third-party testing.
Roundup
Best Vitamin D Supplements 2026: Ranked by Clinical Evidence
42% of adults are deficient. Learn which D3 form, dose, and brand actually raises blood levels — with cofactor guidance and lab-verified picks.
Guide
8 Signs of Magnesium Deficiency – 2026 Guide
Muscle cramps, twitching eyelids, and poor sleep may signal low magnesium. Learn all 8 signs, why standard blood tests miss it, and how to fix it.
Other interactions to know
PPIs can cause hypomagnesemia
High calcium can impair magnesium absorption
Magnesium may enhance BP lowering effect
PPIs impair magnesium absorption
NSAIDs may reduce magnesium levels
Magnesium may reduce thyroid med absorption
Vitamin D and K2 work synergistically
Vitamin D enhances calcium absorption
Check your full stack in the free interaction checker.
The free checker lets you add any combination of supplements and medications at once. The free web app goes further — every stack change surfaces interaction alerts automatically.
Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
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