Magnesium + Vitamin D3 — Supplement Stacking Guide

References

1. Magnesium oxide showed relatively poor bioavailability (fractional absorption ~4%) in normal volunteers, while magnesium chloride, lactate, and aspartate showed significantly higher and equivalent absorption. PubMed
2. Increasing brain magnesium with magnesium-L-threonate enhanced learning, working memory, and short- and long-term memory in rats, accompanied by increased hippocampal synaptic density and enhanced synaptic plasticity. PubMed
3. In a double-blind, placebo-controlled study of 109 healthy Chinese adults, a magnesium L-threonate (Magtein PS) based formula at 2 g/day for 30 days significantly improved memory and overall memory quotient scores versus placebo, with greater improvement in older participants. PubMed
4. In sleep-restricted healthy subjects, 3 g of glycine taken before bedtime reduced subjective daytime sleepiness and fatigue, supporting glycine's independent sleep-related effects (relevant to magnesium glycinate's glycine co-molecule). PubMed
5. This review establishes magnesium as an essential intracellular cation involved in over 600 enzymatic reactions including energy metabolism and protein synthesis, with important physiological roles in the brain, heart, and skeletal systems. PubMed
6. A randomized, double-blind, placebo-controlled trial evaluated MMFS-01 (magnesium L-threonate) in older adults (age 50-70) with cognitive impairment for its ability to reverse cognitive impairment and improve sleep. PubMed
7. This review of the evidence concludes that the propagation of transdermal (topical) magnesium absorption is scientifically unsupported, in contrast to the well-documented effectiveness of oral magnesium supplementation. PubMed
8. An ex-vivo and double-blind crossover study in healthy subjects compared magnesium bioavailability of Sucrosomial® magnesium against magnesium citrate, oxide, and bisglycinate preparations. PubMed
9. This hypothesis paper argues that magnesium and taurine exert complementary actions to lower intracellular free calcium, providing a mechanistic rationale for magnesium taurate's proposed vascular-protective effects. PubMed
10. In a randomized, double-blind, placebo-controlled trial, adults with poor sleep who took magnesium (as bisglycinate) showed a modestly greater improvement in sleep quality than those taking a placebo, an effect that appeared greater in people with lower dietary magnesium intake. PubMed
11. A 2026 randomized, double-blind, placebo-controlled trial found that six weeks of magnesium L-threonate supplementation improved overall cognitive performance and reaction time in adults with self-reported sleep dissatisfaction, compared to placebo. PubMed
12. A 2024 randomized, double-blind, placebo-controlled trial found that adults with self-reported sleep problems who took magnesium L-threonate showed improved deep and REM sleep measures, along with better daytime mood, energy, and alertness, compared to placebo. PubMed
13. Comparative Clinical Study on Magnesium Absorption and Side Effects After Oral Intake of Microencapsulated Magnesium (MAGSHAPE(TM) Microcapsules) Versus Other Magnesium Sources. PubMed
14. A meta-analysis of small trials found older adults taking magnesium fell asleep roughly 17 minutes faster than those on placebo, though the authors rated the evidence as low quality and called for better-designed studies. PubMed
15. In adults with low magnesium levels and high stress, oral magnesium was associated with a substantial reduction in perceived stress over eight weeks, though the trial had no placebo group. PubMed
16. A 2003 randomized, double-blind, placebo-controlled parallel trial in 46 healthy individuals (300 mg elemental magnesium daily for 60 days) found that magnesium citrate and a magnesium amino-acid chelate, analysed together, showed greater absorption than magnesium oxide by 24-hour urinary magnesium; magnesium citrate alone produced the highest serum magnesium, and magnesium oxide did not differ from placebo. PubMed
17. A 1994 randomized crossover trial in patients with ileal resection (n=12) -- a population at elevated risk for magnesium malabsorption -- found no significant overall difference in magnesium absorption between magnesium diglycinate (chelate) and magnesium oxide, but found diglycinate was significantly better absorbed in the subset of patients with the most severe absorption impairment. PubMed
18. A 1990 controlled study found that magnesium citrate was substantially more soluble than magnesium oxide across a range of simulated gastric-acid conditions, and that magnesium absorption (measured by urinary magnesium rise after an oral dose) was significantly higher with magnesium citrate than with magnesium oxide. PubMed
19. Meta-analysis showing vitamin D3 is significantly more efficacious than D2 at raising and maintaining serum 25(OH)D concentrations. PubMed
20. D3 raises serum 25(OH)D more efficiently than equivalent doses of D2, supporting D3 as the preferred supplemental form. PubMed
21. Calcifediol raised total 25(OH)D nearly 2x more effectively than cholecalciferol; 87.5% of calcifediol participants reached sufficiency by week 4 vs 23.1% with D3. PubMed
22. Review of MK-7 (vitamin K2) molecular pathways showing health benefits in osteoporosis, cardiovascular disease, and calcium metabolism through osteocalcin and MGP activation. PubMed
23. High magnesium intake was associated with reduced risk of vitamin D deficiency; enzymes that synthesize and metabolize vitamin D are magnesium-dependent. PubMed
24. The Endocrine Society clinical practice guideline recommends vitamin D supplementation at suggested daily intake and tolerable upper limit levels depending on age and clinical circumstances, with serum 25-hydroxyvitamin D measurement as the initial diagnostic test for those at risk of deficiency. PubMed
25. Skin exposed to winter sunlight in Boston (42.2 degrees N) from November through February produced no previtamin D3, while at 34 degrees N sunlight effectively synthesized previtamin D3 even in mid-winter, defining a latitude-dependent "vitamin D winter." PubMed
26. Multicentre, double blind, placebo controlled, randomised clinical trial evaluated vitamin D supplementation before in vitro fertilisation in women with polycystic ovary syndrome. PubMed
27. In the DepFuD double-blind randomized trial, 281 patients with a major depressive episode received either high-dose (4000 IU) or low-dose (400 IU) vitamin D3 daily for six months; the high-dose group showed no superior reduction in depressive symptoms (MADRS) over the low-dose group. PubMed
28. The D-FISH non-inferiority trial randomized adults with suboptimal 25(OH)D to fish processing by-product-derived versus synthetic vitamin D3 at the same dose (600 IU daily for 12 weeks), comparing the change in plasma 25(OH)D against a pre-specified non-inferiority margin. PubMed
29. A systematic review and meta-analysis evaluated the relative efficacy of vitamin D2 (ergocalciferol) versus vitamin D3 (cholecalciferol) for raising serum vitamin D metabolite levels and functional indicators. PubMed
30. A 2024 meta-analysis confirmed vitamin D3 raised total 25-hydroxyvitamin D more than D2, with body mass index influencing the response. PubMed
31. In older adults, cholecalciferol (D3) raised 25-hydroxyvitamin D somewhat more efficiently than ergocalciferol (D2). PubMed
32. Vitamin D3 showed 87% greater AUC for serum 25(OH)D compared to D2 at equivalent IU doses in RCT PubMed
33. D2 competitively inhibits 25-hydroxylation of endogenous D3, reducing overall vitamin D status when used as supplement PubMed
34. Cochrane meta-analysis: D3 supplementation reduces all-cause mortality while D2 shows no significant effect PubMed
35. Systematic review confirming D3 superiority over D2 for raising and maintaining serum 25(OH)D levels PubMed