The Healthspan Map · Body system

Blood / Hematologic

Conditions in this system

Anemia

Named for a condition in this system

Evidence naming a condition in Blood / Hematologic — 21 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Folate (B9)	Eat enough of	Strong	Established clinical	Folate deficiency is one of the two most common causes of megaloblastic anemia.	Megaloblastic anemia (B12/folate) (opens in a new tab)
Iron	Eat enough of	Strong	Established clinical	Iron deficiency is the leading cause of anemia worldwide.	WHO — Anaemia fact sheet (opens in a new tab)
Iron	Eat enough of	Strong	Established clinical	Iron deficiency is the leading cause of anemia worldwide.	NIH Office of Dietary Supplements — Iron (opens in a new tab)
Vitamin B12	Eat enough of	Strong	Established clinical	B12 deficiency is one of the two most common causes of megaloblastic anemia.	Megaloblastic anemia (B12/folate) (opens in a new tab)
Alcohol — cut back	Do this	Moderate	RCT / meta-analysis	Alcohol raises GI bleeding/ulcer risk and impairs folate use, contributing to anemia.	Alcohol, GI bleeding & folate (opens in a new tab)
Anchor foods	Watch this	Moderate	Review / narrative	Nutrient-dense whole foods supply the iron, B12 and folate needed for red-cell production.	Iron/B12/folate-rich whole foods (opens in a new tab)
Colours a day	Watch this	Moderate	Review / narrative	Colourful produce provides folate and vitamin C that boosts non-heme iron absorption.	Vitamin C & folate from produce (opens in a new tab)
Copper	Eat enough of	Moderate	Review / narrative	Copper deficiency causes an anemia that can mimic iron deficiency.	Copper-deficiency anemia (opens in a new tab)
Supplement discipline	Do this	Moderate	Review / narrative	Appropriate iron/B12/folate supplementation corrects the common nutritional anemias.	Correcting deficiencies via supplements (opens in a new tab)
Vitamin A (RAE)	Eat enough of	Moderate	Review / narrative	Vitamin A deficiency impairs iron mobilisation and contributes to anemia.	Vitamin A & anemia (opens in a new tab)
Vitamin C	Eat enough of	Moderate	Review / narrative	Vitamin C boosts non-heme iron absorption; deficiency can worsen iron-deficiency anemia.	Vitamin C & iron absorption (opens in a new tab)
Calcium	Don't overdo	Emerging	Established clinical	High-dose calcium reduces iron (and zinc) absorption.	NIH Office of Dietary Supplements — Calcium (opens in a new tab)
Calcium	Don't overdo	Emerging	Review / narrative	High-dose calcium reduces iron (and zinc) absorption.	Calcium and iron absorption - mechanisms and public health relevance, Int J Vitam Nutr Res 2010 (opens in a new tab)
Cook real food	Do this	Emerging	Review / narrative	Cooking whole foods (including in cast-iron) supports dietary iron intake.	Cooking (incl. cast-iron) & iron (opens in a new tab)
Protein	Eat enough of	Emerging	Review / narrative	Inadequate protein limits globin and red-cell production.	Protein & red-cell production (opens in a new tab)
Riboflavin (B2)	Eat enough of	Emerging	Review / narrative	Riboflavin deficiency can contribute to anemia via impaired iron handling.	Riboflavin & anemia (opens in a new tab)
Ultra-processed food — cut back	Do this	Emerging	Review / narrative	Ultra-processed diets low in bioavailable iron/B12/folate can contribute to anemia.	UPF displacing nutrient-dense foods (opens in a new tab)
Vitamin B6	Eat enough of	Emerging	Review / narrative	Vitamin B6 deficiency can cause sideroblastic anemia (impaired heme synthesis).	B6 & sideroblastic anemia (opens in a new tab)
Vitamin E	Eat enough of	Emerging	Review / narrative	Vitamin E deficiency can shorten red-cell survival (hemolysis).	Vitamin E & red-cell membranes (opens in a new tab)
Zinc	Eat enough of	Emerging	Review / narrative	Zinc deficiency is associated with anemia in some populations.	Zinc & anemia (opens in a new tab)
Zinc	Don't overdo	Emerging	Mechanistic	Excess zinc induces copper deficiency, which causes anemia.	Zinc excess -> copper-deficiency anemia (opens in a new tab)

Held for the whole system

Evidence held for Blood / Hematologic as a whole — 9 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Vitamin E	Don't overdo	Strong	Established clinical	High-dose alpha-tocopherol supplements inhibit platelet aggregation and antagonize vitamin K, raising bleeding/hemorrhage risk; UL 1,000 mg is set on this hemorrhagic potential.	NIH ODS – Vitamin E; StatPearls (opens in a new tab)
Vitamin K	Eat enough of	Strong	Established clinical	Vitamin K is the cofactor for clotting-factor carboxylation; deficiency impairs coagulation and causes bleeding/hemorrhage (life-threatening intracranial bleeding in newborns).	NIH ODS / LPI – Vitamin K (opens in a new tab)
Vitamin K	Eat enough of	Strong	Established clinical	Vitamin K is the cofactor for clotting-factor carboxylation; deficiency impairs coagulation and causes bleeding/hemorrhage (life-threatening intracranial bleeding in newborns).	Linus Pauling Institute — Vitamin K (opens in a new tab)
Vitamin K	Don't overdo	Moderate	Established clinical	Natural K1/K2 have no UL and very low toxicity, BUT synthetic menadione (K3) causes hemolytic anemia in infants (discontinued); and excess K antagonizes warfarin, reducing anticoagulation and raising clotting risk in those patients.	LPI – Vitamin K (opens in a new tab)
alpha-Linolenic acid (omega-3)	Don't overdo	Moderate	Established clinical	High-dose omega-3 (fish-oil supplements) has an antiplatelet effect that can raise bleeding risk.	Fish-oil / bleeding literature (opens in a new tab)
alpha-Linolenic acid (omega-3)	Don't overdo	Moderate	RCT / meta-analysis	High-dose omega-3 (fish-oil supplements) has an antiplatelet effect that can raise bleeding risk.	"Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis", J Am Heart Assoc 2024 (opens in a new tab)
Calcium	Don't overdo	Emerging	Mechanistic	High calcium intake competitively impairs absorption of iron, zinc and magnesium.	NIH ODS – Calcium (opens in a new tab)
Iron	Don't overdo	Emerging	Mechanistic	High-dose iron competitively decreases zinc absorption.	NIH ODS – Iron (opens in a new tab)
Total Fiber	Don't overdo	Emerging	Established clinical	Very high fiber/phytate can modestly reduce absorption of iron, zinc and calcium.	NIH Office of Dietary Supplements — Iron (opens in a new tab)