01Markers · Blood and iron
Hematocrit
The percentage of blood volume made up of red blood cells.
- Measured in
- Blood (whole blood)
- Units
- %
- Also called
- Hct, packed cell volume, PCV
- Iron
- HIIT
- L-carnitine
- Ashwagandha
- Vitamin C
- Zinc
- NAD+
- Omega-3
- Creatine
- NAC
- Berberine
- Collagen
- Finnish sauna
- L-theanine
- Lion's mane
- Magnesium
- Melatonin
- Milk thistle
- PQQ
- Red yeast rice
- Resveratrol
- Taurine
- Ubiquinol (CoQ10)
- Vitamin D3
- Vitamin E
- Vitamin K2
- Zone 2 cardio
AWhat moves Hematocrit
10 of 27 studied
Moves it5
Human studies found a change. The grade reflects the studies behind it, from A (strongest) to D.
IronRaisesGrade A
Iron raises hematocrit.
Meta-analysis or review · Moderate effect · 12 studies linked
Composite of RBC count, MCV, and MCHC; correlates closely with Hb and serves as transfusion trigger
- Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion: systematic review and meta-analysis of randomised clinical trials (2013)
- Liposomal SunActive versus conventional iron for treatment of iron-deficiency anemia in children aged 2-12 years: a prospective randomized controlled trial. (2025)
- Iron Supplementation After Blood Donation Expedites Hematological Recovery but Does Not Influence Exercise Performance. (2025)
- Dietary supplementation of mineral nanoparticles for channel catfish (Ictalurus punctatus). (2024)
- Efficacy and safety of parenteral nutrition with iron sucrose for anemia prevention in preterm infants: A randomized, double-blind controlled study. (2022)
- Effects of Umbilical Cord Milking on Anemia in Preterm Infants: A Multicenter Randomized Controlled Trial. (2022)
- +6 more studies
HIITRaisesGrade A
HIIT raises hematocrit.
Meta-analysis or review · 3 studies linked
- Acute hematological, metabolic, and inflammatory responses to simulated-6000 ft masked versus unmasked high-intensity interval training in youth soccer players: a randomized crossover pilot study. (2025)
- Evaluating the impact of coenzyme Q10 and high-intensity interval training on lactate threshold and Plasma blood gases in rats: a randomized controlled trial. (2025)
- Change in Central Cardiovascular Function in Response to Intense Interval Training: A Systematic Review and Meta-analysis. (2022)
L-carnitineRaisesGrade A
L-carnitine raises hematocrit.
Meta-analysis or review · Modest effect · 3 studies linked
24 studies; parallels hemoglobin response in dialysis populations. Reflects improved RBC mass.
- Effect of l-carnitine supplementation on renal anemia in patients on hemodialysis: a meta-analysis (2021)
- Effect of combination therapy of hydroxyurea with l-carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with beta-thalassemia intermedia. (2010)
- L-Carnitine supplementation for adults with end-stage kidney disease requiring maintenance hemodialysis: a systematic review and meta-analysis. (2014)
AshwagandhaRaisesGrade B
Ashwagandha raises hematocrit.
Human trials · 2 studies linked
Vitamin CRaisesGrade B
Vitamin C raises hematocrit.
Human trials · 1 study linked
31 studies. Likely parallels hemoglobin in iron-deficiency contexts.
Studied, no change5
Studies looked and found no meaningful change. That is a result, not missing data.
ZincNo changeGrade A
Studies of Zinc found no change in hematocrit.
Meta-analysis or review · 2 studies linked
Hematocrit follows hemoglobin; same safety caveat for high-dose zinc applies.
NAD+No changeGrade A
Studies of NAD+ found no change in hematocrit.
Human trials · 1 study linked
Grade corrected from A to B: single source RCT only.
Omega-3No changeGrade A
Studies of Omega-3 found no change in hematocrit.
Meta-analysis or review · Negligible effect · 1 study linked
CreatineNo changeGrade B
Studies of Creatine found no change in hematocrit.
1 study linked
Hematocrit not significantly changed despite intracellular fluid retention; plasma volume expansion is minimal relative to total blood volume
NACNo changeGrade B
Studies of NAC found no change in hematocrit.
Human trials · Negligible effect · 1 study linked
Not studied17
No usable human study has measured Hematocrit with these. A gap is not a negative result: nobody has looked.
BerberineCollagenFinnish saunaL-theanineLion's maneMagnesiumMelatoninMilk thistlePQQRed yeast riceResveratrolTaurineUbiquinol (CoQ10)Vitamin D3Vitamin EVitamin K2Zone 2 cardio