Hemoglobin
The oxygen delivery system. Hemoglobin is the protein in red blood cells responsible for carrying oxygen from the lungs to every tissue. Each molecule contains four heme groups that bind oxygen. Low hemoglobin causes anemia and fatigue. HbA1c measures glucose bound to hemoglobin—a key diabetes marker.
What Hemoglobin Needs
Iron
Central to each heme group. Most common deficiency causing low hemoglobin.
Vitamin B12
Needed for red blood cell production. Deficiency causes megaloblastic anemia.
Folate
DNA synthesis for new red cells. Works with B12. Deficiency similar effects.
Vitamin B6
Heme synthesis requires B6. Cofactor for ALA synthase. Often overlooked.
Copper
Needed for iron mobilization. Ceruloplasmin. Copper deficiency = anemia.
Riboflavin (B2)
Enhances iron absorption. Supports RBC production.
Causes of Low Hemoglobin
Iron Deficiency
Most common cause. Blood loss, poor intake, poor absorption.
B12/Folate Deficiency
Large, immature red cells. Pernicious anemia. Vegetarians at risk.
Chronic Inflammation
Anemia of chronic disease. Iron trapped in storage. Hepcidin elevated.
Blood Loss
Heavy periods, GI bleeding. Gradual loss depletes iron.
Kidney Disease
Kidneys make erythropoietin. Reduced EPO = reduced RBC production.
Hemolysis
Red cells destroyed prematurely. Autoimmune, genetic, toxins.
HbA1c - Glycated Hemoglobin
What It Measures
Percentage of hemoglobin with glucose attached. Reflects 2-3 month average.
Normal Range
Below 5.7% normal. 5.7-6.4% prediabetes. 6.5%+ diabetes.
Optimal
Functional medicine often targets under 5.3-5.5% for optimal health.
Limitations
Affected by RBC lifespan. Anemia, blood loss can falsely alter results.