Magnesium Citrate vs Vitamin K2 (MK-7)

Sleep vs Vitamin · evidence-backed comparison

Quick take
  • Magnesium Citrate has the broader effect profile across the 9 effect categories.
  • Magnesium Citrate is cheaper per serving ($0.12 vs $0.18).

Side-by-side traits

TraitMagnesium CitrateVitamin K2 (MK-7)
Category
SleepVitamin
Active compound
Magnesium citrateMenaquinone-7
Form available
Capsule, Powder, Tablet, LiquidSoftgel, Capsule
Source
syntheticmicrobial
Typical dose
200–400 mg elemental Mg100–200 mcg daily
Dose range
200–400 mg100–200 mcg
Loading protocol
Best taken with
any time, with waterfat-containing meal
Best time of day
anyany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
High (4/5)High (4/5)
Onset time
Acute: 1–3 hoursCumulative: 4–12 weeks
Half-life
~72 hours
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Low (2/5)
Muscle / strength
Low (2/5)Very Low (1/5)
Physical energy
Low (2/5)Very Low (1/5)
Focus / cognition
Very Low (1/5)Very Low (1/5)
Mood / stress
Low (2/5)Very Low (1/5)
Sleep quality
Moderate (3/5)Very Low (1/5)
Immunity
Very Low (1/5)Low (2/5)
Recovery
Post-exercise recovery support.
Low (2/5)Low (2/5)
Longevity / healthspan
Moderate (3/5)High (4/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.12$0.18
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Magnesium Citrate

Most affordable absorbable magnesium. Doubles as a mild laxative — useful if constipated, less ideal if not.

Active compound: Magnesium citrate
Forms: Capsule, Powder, Tablet, Liquid
Onset: Acute: 1–3 hours
sleepconstipationvaluemuscle

About Vitamin K2 (MK-7)

Activates osteocalcin and matrix-Gla protein to direct calcium into bones rather than arteries. Most evidence comes from the 3-year Rotterdam study.

Active compound: Menaquinone-7
Forms: Softgel, Capsule
Onset: Cumulative: 4–12 weeks
bonearterial-healthcalcium-regulationlongevity

Magnesium Citrate safety

Common side effects:

  • Loose stools (often desired)
  • GI cramps

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

Vitamin K2 (MK-7) safety

Common side effects:

  • Generally none

Avoid if:

  • Warfarin therapy

Drug interactions:

  • Warfarin (major)
  • Other anticoagulants

Common uses

  • General magnesium repletion
  • Constipation
  • Sleep

Stacks well with: Vitamin D3

Common uses

  • Bone density
  • Arterial health
  • Calcium routing

Stacks well with: Vitamin D3, Magnesium Glycinate

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements — especially if you are pregnant, breastfeeding, take prescription medication, or have a chronic condition.