Iron Deficiency Diet: Raising Ferritin With Food and Smart Pairing

Iron deficiency is the most common nutrient deficiency in the world, and the most common cause of anaemia. You can be iron deficient with a completely normal haemoglobin — depleted stores show up in ferritin long before the blood count changes, which is why "my blood count was fine" is not reassurance.

⚠️ Medical disclaimer: Iron deficiency in men and postmenopausal women warrants investigation for gastrointestinal blood loss. Do not supplement iron long-term without testing — iron overload is harmful.

Key takeaways

Ferritin reflects stores and falls first; haemoglobin falls last. Ferritin below ~30 µg/L indicates deficiency in most labs, even without anaemia.
Heme iron (meat, fish, poultry) is absorbed at roughly 15–35%; non-heme iron (plants, fortified foods) at roughly 2–20%, heavily modified by what you eat with it.
Vitamin C dramatically increases non-heme absorption; tea, coffee, calcium and phytates reduce it.
Ferritin rises slowly — expect 2–3 months to see meaningful change, and 3–6 months to refill stores.
Ferritin is an acute-phase reactant: inflammation falsely raises it, so interpret alongside CRP and transferrin saturation.

Symptoms and who is at risk
Understanding your labs
Heme vs non-heme: the absorption gap
Enhancers and inhibitors
Best food sources
A 7-day iron-focused menu
When food is not enough: supplements
FAQ
Sources

1. Symptoms and who is at risk

Symptoms: fatigue disproportionate to activity, breathlessness on stairs, pallor (especially conjunctiva and palm creases), cold hands and feet, brittle or spoon-shaped nails, hair shedding, headaches, restless legs, reduced exercise tolerance, and pica (craving ice, clay or starch).

Highest-risk groups:

Menstruating women, particularly with heavy periods
Pregnancy (requirements roughly double in the second and third trimester)
Vegetarians and vegans (non-heme only, plus phytate load)
Endurance athletes (foot-strike haemolysis, hepcidin rise, sweat losses)
Frequent blood donors
Coeliac disease, IBD, H. pylori gastritis, bariatric surgery
Regular NSAID or PPI users
Infants, toddlers and adolescents in growth spurts

2. Understanding your labs

Marker	What it tells you	Deficiency pattern
Ferritin	Iron stores	Low (<30 µg/L; <15 is definite)
Haemoglobin	Oxygen-carrying capacity	Low only once stores are exhausted
MCV	Red cell size	Low (microcytic)
Transferrin saturation	Iron available for use	<20%
TIBC	Transport capacity	High
CRP	Inflammation	If raised, ferritin is unreliable

With inflammation present, a ferritin up to 100 µg/L can still coexist with deficiency — transferrin saturation becomes the more useful marker. See our blood work reading guide.

3. Heme vs non-heme: the absorption gap

Heme iron comes from haemoglobin and myoglobin in animal tissue. It uses a dedicated transporter, is absorbed at roughly 15–35%, and is largely unaffected by other foods in the meal.

Non-heme iron is in plants, eggs, dairy and fortified foods. Absorption ranges from about 2% to 20% depending entirely on the meal context. This is the lever you control.

Practical consequence: a vegetarian aiming to correct deficiency needs both a higher intake and deliberate pairing. Requirements for vegetarians are often estimated at roughly 1.8× those of omnivores.

4. Enhancers and inhibitors

Enhancers

Vitamin C — 75–100 mg with a meal can multiply non-heme absorption several-fold. A whole orange, 100 g red pepper, or 150 ml orange juice does it.
Meat/fish/poultry factor — even a small amount of animal protein improves non-heme absorption from the same meal.
Acidic cooking — tomato-based sauces, lemon, vinegar.
Fermentation and sprouting — reduces phytate.
Cast iron cookware — a genuine, if modest, contribution with acidic foods.

Inhibitors

Tea and coffee — polyphenols can cut absorption by up to 50–90%. Move them 1–2 hours away from iron-containing meals. This is the single highest-yield change for many people.
Calcium — 300 mg+ (a glass of milk, a large yoghurt) competes with iron. Separate dairy from your iron meal.
Phytates — wholegrains, legumes, nuts. Soak, sprout or ferment.
Polyphenols in red wine, cocoa, some herbal teas.
PPIs and antacids — reduced stomach acid impairs non-heme absorption.

5. Best food sources

Food	Serving	Iron	Type
Lamb's liver	100 g	~7 mg	Heme
Beef steak	150 g	~4 mg	Heme
Sardines (canned)	100 g	~2.9 mg	Heme
Mussels	100 g	~6.7 mg	Heme
Chicken thigh	150 g	~1.5 mg	Heme
Lentils (cooked)	200 g	~6.6 mg	Non-heme
Tofu (firm)	150 g	~4 mg	Non-heme
Pumpkin seeds	30 g	~2.5 mg	Non-heme
Spinach (cooked)	150 g	~4 mg	Non-heme
Fortified cereal	40 g	4–8 mg	Non-heme
White beans	200 g	~6 mg	Non-heme
Dark chocolate 70%	30 g	~3.4 mg	Non-heme

Note: liver is exceptionally iron-dense but should be avoided in pregnancy because of its vitamin A content.

6. A 7-day iron-focused menu

Each day pairs a major non-heme source with vitamin C and keeps tea/coffee away from meals.

Day 1 — Fortified oats with strawberries; lentil and tomato soup with red pepper; beef stir-fry with broccoli and rice.
Day 2 — Eggs on wholegrain toast with grilled tomato; tuna salad with orange segments; lamb and chickpea tagine with lemon.
Day 3 — Smoothie with spinach, kiwi and pumpkin seeds; sardines on sourdough; chicken thigh with roast potato and broccoli.
Day 4 — Fortified cereal with berries; white bean salad with peppers and lemon; mussels in tomato broth with bread.
Day 5 — Tofu scramble with peppers; leftover mussels; steak, sweet potato and kale with lemon.
Day 6 — Yoghurt-free overnight oats with citrus; lentil dahl with tomato; salmon, quinoa and broccoli.
Day 7 — Eggs and spinach; chicken and bean burrito bowl with salsa; liver and onions with mash (skip in pregnancy) or beef mince bolognese.

Timing rule that matters most: coffee and tea at least one hour before or two hours after any iron-containing meal.

7. When food is not enough: supplements

Diet alone rarely refills severely depleted stores in a reasonable timeframe. Typical clinical practice:

Elemental iron 40–100 mg, taken on alternate days — alternate-day dosing raises fractional absorption by avoiding the hepcidin spike that follows a dose, and improves tolerability.
Take on an empty stomach with vitamin C if tolerated; with a small amount of food if not.
Ferrous sulfate, fumarate and gluconate all work; the differentiator is elemental iron content and side effects.
Expect dark stools — this is harmless. Constipation is common; pair with fluid and soluble fibre.
Retest ferritin at 3 months. Continue for 3 months after normalisation to refill stores.
Non-responders need investigation: ongoing blood loss, coeliac disease, H. pylori, or malabsorption.

Upload your blood work to Nutrtion.io — the app tracks ferritin, haemoglobin and transferrin saturation over time and builds an iron-focused food plan around your actual numbers and your meal-timing habits.

FAQ

How long does it take to raise ferritin? Haemoglobin usually responds within 2–4 weeks of effective treatment; ferritin takes 3–6 months to refill.

Is spinach a good iron source? It contains iron, but its oxalate content limits absorption. Cook it and pair with vitamin C; do not rely on it alone.

Can I take iron and calcium together? Better not. Separate them by at least two hours.

Do I need iron if my haemoglobin is normal? You can be iron deficient without anaemia. Symptoms often respond to correcting ferritin even with a normal blood count.

Is too much iron dangerous? Yes. Unnecessary supplementation can cause gastrointestinal harm and, in haemochromatosis, organ damage. Test before treating.

Sources

NIH Office of Dietary Supplements. Iron — Health Professional Fact Sheet. 2024.
Stoffel NU, et al. Iron absorption from oral iron supplements given on consecutive versus alternate days. Lancet Haematol. 2017.
Hurrell R, Egli I. Iron bioavailability and dietary reference values. Am J Clin Nutr. 2010.
Camaschella C. Iron deficiency. Blood. 2019.
World Health Organization. Guideline on use of ferritin concentrations to assess iron status. 2020.