Anemia and Brain Fog
Guideline: NICE NG203 Anaemia; WHO Guidelines
What Is Anemia-Related Brain Fog?
Not enough red blood cells to carry oxygen to your brain. The result: fatigue + fog + pale skin + dizziness + shortness of breath on exertion. Your brain is literally oxygen-deprived.
What to Do This Week
Seven actionable steps you can start today — free, evidence-based, and designed for when you're foggy.
Body
Rest if severely fatigued. Your body is oxygen-deprived. Gradual increase in activity as levels improve.
Food
Red meat, liver, shellfish, dark leafy greens with lemon/citrus (vitamin C enhances absorption).
Water
Stay hydrated. Iron supplements can cause constipation — increase water and fiber.
Environment
If severely anemic, avoid strenuous activity until levels improve.
Connection
Tell people you're anemic — fatigue is real, not laziness.
Tracking
Track energy levels as you supplement. Retest ferritin after 3-4 months.
Avoid
Don't take iron with calcium, dairy, or tea. Don't stop supplementing when you feel better — continue until ferritin is fully replete.
What to Eat: The Iron and B12 Rich Approach
Focus on bioavailable iron and B12 from animal sources, with vitamin C to enhance absorption.
Sample Day
- breakfast: 2 eggs scrambled in olive oil + handful spinach + slice sourdough + blueberries
- lunch: Big salad (mixed greens, chickpeas, cucumber, tomato, feta, olive oil + lemon) + water
- snack: Apple + handful walnuts or almonds
- dinner: Salmon or chicken thigh + roasted vegetables (broccoli, sweet potato, red onion) + olive oil
- evening: Herbal tea (chamomile or peppermint)
For Anemia: Heme iron (animal sources) is 2-3x better absorbed than plant iron. Take iron supplements away from tea, coffee, and calcium.
This is a PATTERN, not a prescription. Adapt to your budget, culture, preferences, and what's available. The principles matter more than perfection: more plants, good fats, less processed food.
When to Seek Urgent Help
STOP — Seek urgent medical evaluation if: sudden onset of cognitive symptoms (hours/days), severe fatigue with rapid heart rate or chest pain, blood in stool or black tarry stools, heavy menstrual bleeding, or rapidly progressive symptoms. These may indicate a medical emergency.
Tests and Investigations
Anemia Testing
- CBC (complete blood count) — hemoglobin, MCV, MCH
- Ferritin (iron stores) — optimal 40-100 ng/mL, not just 'normal'
- Serum iron and TIBC (total iron binding capacity)
- B12 and folate
- Reticulocyte count (if anemia confirmed)
Low ferritin with normal hemoglobin = iron depletion without anemia (still causes symptoms). Low MCV = iron deficiency. High MCV = B12 or folate deficiency. Ferritin 15-30 is 'normal range' but often symptomatic — optimal is 40-100.
Investigate Cause (if anemia confirmed)
- Celiac screen (tTG-IgA) — celiac causes iron malabsorption
- H. pylori testing — can cause iron deficiency
- Stool occult blood — rule out GI bleeding
- Menstrual history in women — heavy periods are common cause
Don't just treat anemia — find WHY you're anemic. Malabsorption, blood loss, and inadequate intake need different approaches.
Evidence-Based Lifestyle Changes
Iron-Rich Foods
Red meat, organ meats, shellfish, legumes, dark leafy greens. Pair plant iron with vitamin C to enhance absorption. Avoid tea/coffee with iron-rich meals (inhibits absorption).
Evidence: Strong for dietary iron intake
B12-Rich Foods
Animal products: meat, fish, eggs, dairy. Vegans require supplementation as B12 is only reliably found in animal foods.
Evidence: Strong
Holistic Support
Investigate root cause
Strong — anemia is a symptom, not a diagnosis
Check for celiac, GI bleeding, heavy periods, malabsorption. Treat the cause, not just the symptom.
Absorption optimization
Strong — iron absorption is affected by many factors
Take iron with vitamin C. Avoid tea/coffee within 2 hours. Consider every-other-day dosing.
Medical Treatment Options
Discuss these options with your prescribing physician. This information is educational, not medical advice.
Iron Supplementation (if iron-deficient)
Ferrous sulfate, ferrous gluconate, or ferrous bisglycinate. Take with vitamin C on empty stomach for best absorption. Every-other-day dosing may improve absorption.
Evidence: Strong
B12 Supplementation/Injections
Oral methylcobalamin 1000-2000mcg daily, or B12 injections if absorption is impaired.
Evidence: Strong
Iron Infusion (if severe or not responding)
IV iron infusion if oral iron not tolerated or not effective. Discuss with your doctor.
Evidence: Strong for refractory cases
Supplements — What the Evidence Says
Supplements are adjuncts, not replacements for lifestyle changes. Discuss with your healthcare provider.
Vitamin C with Iron
Dose: 200-500mg vitamin C taken with iron supplement
Vitamin C enhances non-heme iron absorption significantly.
Psychological Support and Therapy
Usually not needed. Medical management primary. If fatigue is affecting mental health, consider supportive counseling.
What People With Anemia Brain Fog Say
What Helped
- • Getting ferritin checked — was 'normal' at 18, but symptoms resolved when it reached 70
- • Iron bisglycinate instead of ferrous sulfate — much fewer side effects
- • Taking iron every other day — research shows better absorption than daily
- • B12 injections when oral supplements weren't working
What Didn't Help
- • Taking iron with tea or coffee — blocks absorption
- • Calcium supplements at the same time as iron — blocks absorption
- • Assuming 'normal' ferritin was fine — optimal is higher than 'normal range'
Common Mistakes
- • Taking iron with calcium or dairy — separate by 4 hours
- • Not investigating WHY you're anemic — could be celiac, bleeding, or other cause
- • Stopping iron when you feel better — need to continue until ferritin is replete
Surprises
- • Ferritin of 15-30 is considered 'normal' but many people are symptomatic until it reaches 50+
- • Iron deficiency without anemia (low ferritin, normal hemoglobin) still causes significant symptoms
- • B12 deficiency can cause irreversible neurological damage if untreated — take it seriously
"Ferritin optimal range (40-100 ng/mL) is different from 'normal' range. If your ferritin is 15 and the lab says 'normal,' you may still be symptomatic. Many people feel significantly better when ferritin reaches 50-70."
Quick Reference
Quick Win
Request a CBC (complete blood count) and ferritin from your doctor. Ferritin under 30 ng/mL is associated with cognitive symptoms even without frank anemia. If low, discuss supplementation with your doctor.
NICE NG203 Anaemia; WHO Haemoglobin Concentrations