Iron Bisglycinate vs Vitamin D3
Mineral vs Vitamin · evidence-backed comparison
- • Vitamin D3 has the broader effect profile across the 9 effect categories.
- • Vitamin D3 is cheaper per serving ($0.08 vs $0.18).
- • Vitamin D3 has a slightly cleaner safety profile.
- • Iron Bisglycinate has higher bioavailability (better absorption).
Side-by-side traits
| Trait | Iron Bisglycinate | Vitamin D3 |
|---|---|---|
Category | Mineral | Vitamin |
Active compound | Ferrous bisglycinate | Cholecalciferol |
Form available | Capsule, Tablet | Softgel, Capsule, Liquid, Tablet |
Source | synthetic | animal |
Typical dose | 18–25 mg elemental iron | 1000–4000 IU daily |
Dose range | 18–25 mg | 1000–4000 IU |
Loading protocol | — | — |
Best taken with | vitamin C, empty stomach (or with food if GI sensitive) | fat-containing meal |
Best time of day | morning | morning |
Bioavailability How efficiently the body absorbs and utilizes the compound. | Very High (5/5) | High (4/5) |
Onset time | Cumulative: 4–12 weeks | Cumulative: 8–12 weeks |
Half-life | — | ~3 weeks |
Evidence level Quality and quantity of human research. | Strong (multiple RCTs / meta-analyses) | Strong (multiple RCTs / meta-analyses) |
Overall effect Subjective effect magnitude. | Moderate (3/5) | Moderate (3/5) |
Muscle / strength | Low (2/5) | Moderate (3/5) |
Physical energy | High (4/5) | Moderate (3/5) |
Focus / cognition | Moderate (3/5) | Low (2/5) |
Mood / stress | Moderate (3/5) | High (4/5) |
Sleep quality | Low (2/5) | Moderate (3/5) |
Immunity | Low (2/5) | Very High (5/5) |
Recovery Post-exercise recovery support. | Moderate (3/5) | Moderate (3/5) |
Longevity / healthspan | Very Low (1/5) | High (4/5) |
Safety rating 5 = exceptionally well-tolerated; 1 = significant risk profile. | Moderate (3/5) | High (4/5) |
Price per serving Approximate USD per typical daily dose. | $0.18 | $0.08 |
Vegan friendly | Yes | No |
Gluten free | Yes | Yes |
3rd-party tested | Yes | Yes |
About Iron Bisglycinate
Best-tolerated iron form for treating deficiency anemia. Don't supplement without a confirmed low ferritin / low Hgb test.
About Vitamin D3
Most adults are deficient. Affects 1000+ genes including immunity, mood, and bone health. Pair with K2 to direct calcium into bones, not arteries.
Vetted brands, third-party testing, ships worldwide.
Vetted brands, third-party testing, ships worldwide.
Iron Bisglycinate safety
Common side effects:
- • Constipation (less than ferrous sulfate)
- • Dark stools
Avoid if:
- • Hemochromatosis
- • Iron overload
- • Untested males without deficiency
Drug interactions:
- • Levothyroxine
- • Calcium
- • PPIs
Vitamin D3 safety
Common side effects:
- • Hypercalcemia (very high doses)
Avoid if:
- • Hyperparathyroidism
- • Sarcoidosis
- • Kidney stones
Drug interactions:
- • Statins
- • Thiazide diuretics
- • Steroids
Common uses
- • Anemia treatment
- • Heavy menstruation
- • Endurance athletes
Stacks well with: Vitamin C
Common uses
- • Deficiency correction
- • Bone health
- • Immune support
- • Mood / SAD
Stacks well with: Vitamin K2 (MK-7), Magnesium Glycinate
Related comparisons
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.