Primary Causes & Action Plans
Vitamin B12
Intrinsic factor deficiency or intestinal damage impairs B12 absorption B12 is absorbed in terminal ileum; malabsorption occurs with celiac disease, pernicious anemia, or bacterial overgrowth. Deficiency causes anemia, neuropathy, and cognitive decline.
Target > 500 pg/mL
Suggested Action Plan
If low from malabsorption, B12 injections bypass GI absorption. B12 injections (1000 mcg monthly) are more effective than oral supplements for malabsorption-based deficiency.
Folate
Absorbed in small intestine; inflammation or dysbiosis impairs absorption Folate malabsorption occurs with celiac disease, small intestinal bacterial overgrowth (SIBO), and leaky gut. Deficiency causes anemia and birth defects.
Target > 8 ng/mL
Suggested Action Plan
Supplement with methylfolate if malabsorption is present. Simultaneously address underlying cause (gluten elimination, antimicrobial therapy, gut healing).
Iron and Ferritin
Intestinal inflammation impairs iron absorption Celiac disease, inflammatory bowel disease, and leaky gut all impair iron absorption. Iron deficiency causes anemia, fatigue, and cognitive dysfunction.
Target Ferritin 50-150 ng/mL
Suggested Action Plan
Iron supplementation with vitamin C enhances absorption. If malabsorption is severe, IV iron may be needed. Address underlying intestinal inflammation simultaneously.
Fat-Soluble Vitamins (A, D, E, K)
Bile deficiency or intestinal damage impairs fat-soluble vitamin absorption Fat-soluble vitamins require bile and healthy intestinal epithelium for absorption. Biliary dysfunction or intestinal disease causes deficiency.
Target Vitamin D > 50 ng/mL; others adequate ranges
Suggested Action Plan
Supplement with emulsified or liquid forms that do not require intact fat absorption. Simultaneously restore bile function and intestinal health.