Natural Iron Supplements and Food Sources

By Dr (TCM) Attilio D'Alberto | Traditional Chinese Medicine Practitioner, Wokingham

Iron deficiency is the most common nutritional deficiency in the world. In the UK, around 1 in 4 women of reproductive age has low iron stores (low ferritin) even when haemoglobin is in the normal range, and the proportion rises further in pregnancy, postnatal women, vegetarians, vegans, women with heavy periods, those with endometriosis or fibroids, and women trying to conceive. The fatigue, low mood, hair loss, brain fog, scant periods and fertility difficulty that result are routinely missed because GPs often only check haemoglobin and not ferritin — and a "normal" haemoglobin with very low ferritin is functionally still iron deficient. From a TCM perspective, iron deficiency maps closely to blood deficiency. This page covers everything: when to suspect iron deficiency, what to test, the best food sources, the best supplement form, what blocks absorption, and how Chinese herbs support the picture.

On this page

1. Why iron matters
2. Signs of iron deficiency
3. Essential tests — beyond haemoglobin
4. Causes of iron deficiency
5. Haem vs non-haem iron
6. Best iron-rich foods
7. Maximising absorption
8. Absorption blockers to avoid
9. Iron supplements — the best forms
10. Dosing and timing
11. Managing side effects
12. Alternate-day dosing — the new evidence
13. TCM blood-deficiency treatment
14. Iron in pregnancy
15. Iron and fertility
16. FAQs

Why iron matters

• Haemoglobin synthesis — carries oxygen to every tissue.
• Myoglobin — oxygen storage in muscle.
• Energy production — central to mitochondrial electron transport.
• Neurotransmitter synthesis — dopamine, serotonin, noradrenaline.
• Thyroid function — needed for T4 production and T3 conversion.
• Immune function.
• DNA synthesis and cell division.
• Brain development in pregnancy and infancy.
• Hair growth — low ferritin is the most common cause of telogen effluvium hair loss in women.
• Egg quality and fertility.

Signs of iron deficiency

• Persistent fatigue, low energy.
• Pallor — pale inner eyelids, nail beds, gums.
• Cold hands and feet.
• Shortness of breath on exertion.
• Palpitations, particularly on exercise.
• Brittle nails — sometimes spoon-shaped (koilonychia).
• Hair loss / hair thinning.
• Headaches.
• Brain fog, poor concentration.
• Restless legs syndrome — strongly associated with low ferritin.
• Scant or pale menstrual flow.
• Anxiety, low mood.
• Pica (cravings for ice, chalk, dirt) — characteristic.
• Cracking at corners of mouth.
• Sore tongue (glossitis).
• Decreased exercise tolerance.

Essential tests — beyond haemoglobin

Many GPs only check haemoglobin (Hb). This misses early/functional iron deficiency. The full picture needs:

• Haemoglobin (Hb) — anaemia diagnosed below 120 g/L in women.
• Mean corpuscular volume (MCV) — low (microcytic) in iron-deficiency anaemia.
• Mean corpuscular haemoglobin (MCH) — low (hypochromic) in iron deficiency.
• Ferritin — the key test. Reflects iron stores.
  • NHS lab "normal" ranges go down to 12-15 ng/mL — this is too low.
  • Aim for ferritin >30 ng/mL for general health.
  • Aim for ferritin >50 ng/mL if trying to conceive or restless legs.
  • Aim for ferritin >70 ng/mL if hair loss.
• Transferrin saturation — <20% suggests deficiency; >45% suggests overload.
• CRP — ferritin is also an acute-phase reactant; can be falsely high in inflammation. Check CRP alongside.
• Vitamin B12 and folate — often coexist with iron deficiency.
• If repeated low ferritin without obvious cause — coeliac screen (tTG IgA), faecal calprotectin, FOBt (or FIT) for occult bleeding.

Causes of iron deficiency

• Heavy or prolonged menstrual bleeding — leading cause in reproductive-age women.
• Pregnancy — iron requirement doubles.
• Postpartum — particularly with significant bleeding at birth.
• Inadequate dietary intake — particularly in vegetarians, vegans, restrictive eaters.
• Coeliac disease — impaired absorption; sometimes silent.
• Inflammatory bowel disease (Crohn's, UC) — combined poor absorption and chronic blood loss.
• H. pylori infection — under-recognised cause of iron malabsorption.
• Atrophic gastritis or low stomach acid — impairs iron absorption.
• PPIs and antacids — long-term use reduces iron absorption.
• Bariatric surgery — particularly gastric bypass.
• GI bleeding — ulcers, polyps, tumours; needs investigation in older adults.
• Endometriosis and fibroids — heavy bleeding.
• Frequent blood donation.
• Endurance athletes — combined haemolysis, GI losses, sweat losses.
• Hookworm — rare in UK; relevant in immigrant patients.

Haem vs non-haem iron

• Haem iron — found in animal foods (meat, fish, poultry). Absorbed at 15-35% regardless of body iron status. The most bioavailable dietary form.
• Non-haem iron — found in plant foods. Absorbed at 2-20%; absorption is regulated by body iron status (more absorbed when deficient). Significantly enhanced by vitamin C; significantly inhibited by tannins and phytates.
• Practical implication — vegetarians and vegans need 1.8x the RDA of iron from food, and need to be more deliberate about absorption-enhancing combinations.

Best iron-rich foods

By portion (typical serving):

• Liver (beef, chicken, lamb, duck) — 100 g: 6-12 mg haem iron. The single richest source.
• Oysters — 6 medium: 8 mg haem iron.
• Beef steak — 150 g: 4-5 mg haem iron.
• Lamb — 150 g: 3-4 mg haem iron.
• Sardines — 100 g tin: 2-3 mg haem iron.
• Mussels — 100 g: 7 mg haem iron.
• Black pudding — 100 g: 7-20 mg haem iron (variable).
• Pumpkin seeds — 30 g: 4-5 mg non-haem iron.
• Lentils (cooked) — 200 g: 6-7 mg non-haem iron.
• Chickpeas (cooked) — 200 g: 5 mg non-haem iron.
• Spinach (cooked) — 150 g: 4 mg non-haem iron.
• Tofu (firm) — 150 g: 4 mg non-haem iron.
• Quinoa (cooked) — 200 g: 3 mg non-haem iron.
• Dark chocolate (70%+) — 30 g: 3 mg non-haem iron.
• Dried apricots — 50 g: 1.5 mg non-haem iron.
• Fortified breakfast cereals — variable; check label.

TCM blood-building foods that double as iron sources: black sesame seeds, beetroot, black beans, red dates, slow-cooked meats, bone broth.

Maximising absorption

• Vitamin C with iron — the single most important enhancer. Squeeze lemon over greens, drink orange juice with iron-rich meals, eat peppers/strawberries with beans.
• Combine plant and animal iron — meat factor enhances non-haem absorption.
• Cook in cast iron — particularly acidic dishes (tomato sauce); modest iron leaching into food.
• Soaking and sprouting beans/grains — reduces phytate content.
• Fermented foods — sourdough, kimchi, sauerkraut, miso — better iron absorption than unfermented equivalents.
• Adequate stomach acid — H. pylori treatment, reducing PPI use where possible.
• Treat coeliac disease and gut inflammation — iron absorption recovers as gut heals.

Absorption blockers to avoid

• Tea (including green and herbal) — tannins block iron absorption by 60-90%. Don't drink tea with iron-rich meals or iron supplements; wait 1-2 hours.
• Coffee — similar effect to tea; separate from iron meals.
• Dairy and calcium supplements — calcium competes with iron at absorption sites; separate by 2 hours.
• Antacids and PPIs — reduce stomach acid needed for iron absorption.
• Phytates in unsoaked wholegrains and legumes — soak overnight to reduce.
• Wine, particularly red wine — tannins.
• Egg yolks — phosvitin inhibits iron absorption (don't worry about this if eating varied diet).
• Soy isoflavones — modest inhibitory effect; not a deal-breaker.

Iron supplements — the best forms

• Ferrous bisglycinate (chelated iron) — best tolerated; minimal GI side effects; well absorbed. Brands: Floradix capsules, Solgar Gentle Iron, Pure Encapsulations OptiFerin-C, Better You iron spray.
• Heme iron polypeptide — highly absorbable; expensive; specialist use.
• Ferrous sulphate — most commonly NHS-prescribed (cheap); high GI side effect rate (constipation, nausea).
• Ferrous fumarate — also commonly prescribed; better tolerated than sulphate.
• Ferrous gluconate — better tolerated than sulphate; weaker.
• Liquid iron (Floradix, Spatone) — gentle; lower elemental dose; good for sensitive stomachs.
• Iron infusion (IV) — for severe deficiency, malabsorption, or oral intolerance; given in hospital.
• Lactoferrin — supports iron uptake without giving iron itself; useful adjunct, particularly with PPI use.

Dosing and timing

• Maintenance dose: 14-20 mg elemental iron daily for general health.
• Repletion dose for confirmed deficiency: 60-200 mg elemental iron daily.
• Pregnancy: 30-50 mg elemental iron daily (or higher with confirmed deficiency).
• Take on an empty stomach if tolerated — better absorption.
• Take with vitamin C — orange juice, vitamin C tablet, or vitamin C-rich food.
• Separate from tea, coffee, dairy, calcium by 2 hours.
• Allow 3-6 months to restore ferritin even with consistent supplementation.
• Re-test ferritin and Hb at 3 months, then 6 months, then annually.
• Continue at maintenance dose for at least 3 months after ferritin is in good range.

Managing side effects

Constipation, nausea, dark stools, metallic taste are common with iron — particularly ferrous sulphate. To manage:

• Switch to ferrous bisglycinate — much better tolerated.
• Take with food if empty stomach causes nausea (small absorption cost).
• Try liquid form — Floradix or Spatone.
• Increase magnesium and water for constipation.
• Take alternate days rather than daily (see below).
• Add lactoferrin to boost absorption from a smaller iron dose.
• If genuinely intolerant of all oral forms — consider IV infusion via your GP.

Alternate-day dosing — the new evidence

Recent research (Stoffel et al, Lancet Haematology 2017; subsequent studies) has shown that alternate-day dosing often produces better total iron absorption than daily dosing:

• Iron supplementation acutely raises hepcidin (the iron-regulating hormone) for 24+ hours.
• Hepcidin reduces iron absorption from subsequent doses.
• Alternate-day dosing lets hepcidin fall between doses, improving cumulative absorption.
• Side effects also improve with alternate-day dosing.
• Particularly applicable to non-pregnant women using oral iron for repletion.
• Practical: 60-100 mg elemental iron every other day (or even every third day) with vitamin C, on an empty stomach, often produces better results than daily dosing with fewer side effects.

TCM blood-deficiency treatment

Chinese herbal medicine addresses blood deficiency at a systemic level — not just by providing iron but by improving the body's ability to produce, circulate and store blood:

• Si Wu Tang — Four Substances Decoction; the foundation blood-nourishing formula.
• Ba Zhen Tang — Eight Treasure Decoction; combined qi and blood deficiency. The workhorse for postnatal and post-heavy-period recovery.
• Dang Gui Bu Xue Tang — Tonify Blood Decoction; just two herbs (Huang Qi 30 g and Dang Gui 6 g); classical anaemia formula.
• Gui Pi Tang — Heart and Spleen blood deficiency with anxious-tired insomnia.
• Shi Quan Da Bu Tang — Ten All-Powerful Great Tonic; severe combined deficiency with cold.
• Ren Shen Yang Rong Tang — chronic deficiency.

Key herbs include Dang Gui, Shu Di Huang, Bai Shao, Chuan Xiong (the Si Wu Tang quartet); E Jiao (donkey-hide gelatin); Huang Qi (qi-tonifying); Gou Qi Zi and Long Yan Rou (gentle daily tonics).

TCM treatment combines well with iron supplementation. Pharmaceutical-grade granules from Sun Ten Taiwan.

Iron in pregnancy

• Iron requirements increase significantly — pregnancy doubles total iron needed.
• Aim ferritin >50 ng/mL preconception and through pregnancy.
• Standard prenatal multivitamin contains 14-20 mg elemental iron — often not enough.
• Many pregnant women need 30-60 mg additional elemental iron, particularly from second trimester onwards.
• Pregnancy iron deficiency increases risk of preterm birth, low birth weight, and developmental issues in the baby.
• Postnatal: continue iron for at least 3 months after birth, particularly if significant blood loss at delivery or heavy postnatal bleeding.
• Breastfeeding: maternal iron stores are protected (less is transferred to milk than people think) but maternal anaemia is associated with maternal fatigue and low mood.

Iron and fertility

• Low ferritin reduces fertility — observational evidence and biologically plausible.
• Aim ferritin >50 ng/mL preconception — improves both natural conception and IVF outcomes.
• Iron supports thyroid function — needed for T4 production and T3 conversion; thyroid affects fertility.
• Iron supports egg quality — mitochondrial function needs iron.
• Test ferritin in any woman with fertility difficulty.
• Address heavy menstrual bleeding — both for fertility and to prevent ongoing iron loss.

Frequently asked questions

What's the best iron supplement?

Ferrous bisglycinate (chelated iron) is the best tolerated form. Brands include Solgar Gentle Iron, Floradix Iron Tablets, Pure Encapsulations OptiFerin-C. Avoids the constipation and nausea of ferrous sulphate.

What level should my ferritin be?

Aim >30 ng/mL for general health, >50 ng/mL for fertility and restless legs, >70 ng/mL for hair loss. NHS lab "normal" goes down to 12-15 — that's too low.

Does the type of iron supplement really matter?

Yes — ferrous bisglycinate is much better tolerated than ferrous sulphate (the cheap NHS standard). Many women who give up on iron because of GI side effects do fine on bisglycinate.

Should I take iron daily or alternate days?

Recent evidence supports alternate-day dosing for many non-pregnant adults — better total absorption and fewer side effects. Take 60-100 mg elemental iron every other day with vitamin C on an empty stomach.

What blocks iron absorption?

Tea, coffee, dairy, calcium supplements, antacids, PPIs, and phytates in unsoaked grains/legumes. Separate from iron meals or supplements by 2 hours.

Why am I still iron-deficient despite supplementation?

Common reasons: ferrous sulphate intolerance leading to skipping doses; tea or coffee with the iron; coeliac disease or other malabsorption; PPI use; H. pylori infection; ongoing heavy menstrual bleeding faster than replenishment; absorption competition.

Can I get enough iron from a vegetarian/vegan diet?

Yes with care — combine non-haem iron sources with vitamin C, soak grains and legumes, eat plenty of dark leafy greens, lentils, beans, pumpkin seeds. Many vegetarians and most vegans need supplementation; check ferritin yearly.

To discuss iron deficiency, blood deficiency or fertility nutrition, contact me or book a consultation at my Wokingham clinic.

Related reading: Blood-building herbs | Heavy/prolonged periods | Spirulina benefits

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