Platelet Count

When low (thrombocytopenia, <150 x10^9/L):

Possible causes in athletes:

• Chronic NSAID use (ibuprofen, naproxen) can suppress platelets
• Rarely, certain AAS may affect bone marrow production
• Heavy alcohol use, viral infections (EBV, hepatitis), autoimmune conditions

Supplements:

• Vitamin B12 (Methylcobalamin) -- 1000mcg/day (deficiency impairs platelet production)
• Folate (Methylfolate) -- 800mcg/day
• Vitamin C -- 1-2g/day (supports platelet function)
• Papaya Leaf Extract -- 1100mg/day (emerging evidence for raising platelet count)

Lifestyle:

• Discontinue NSAIDs if possible
• Avoid aspirin and fish oil if platelets are very low (<100)
• Investigate cause if persistent -- haematology referral if <100 x10^9/L

When high (thrombocytosis, >400 x10^9/L):

• Usually reactive: infection, inflammation, iron deficiency, post-exercise
• Persistent elevation >450 without obvious cause warrants haematology review to rule out myeloproliferative disorders
• Iron deficiency (from blood donation) is a common and treatable cause of reactive thrombocytosis

References:

• Stabler, S. P. (2013). Vitamin B12 deficiency. New England Journal of Medicine, 368(2), 149-160. DOI: 10.1056/NEJMcp1113996
• Bailey, L. B., & Gregory, J. F., III. (1999). Folate metabolism and requirements. Journal of Nutrition, 129(4), 779-782. DOI: 10.1093/jn/129.4.779
• Camaschella, C. (2015). Iron-deficiency anemia. New England Journal of Medicine, 372(19), 1832-1843. DOI: 10.1056/NEJMra1401038