JSHealth Iron

Iron is one of the few things on our shelves where the honest answer starts with a blood test, so these are the questions our naturopaths ask in store before you buy a bottle.

A good fit if

• An iron study or ferritin test has shown your stores are low, and your doctor agrees you should top them up
• You're vegetarian or vegan, or eat little meat, and you've had your iron checked rather than guessing
• You have heavy periods and a low test result, and want a maintenance dose between check-ups
• A stronger iron product left you constipated or nauseous and you want a lower-dose option
• You want to understand elemental iron on a label before you compare products

Check with us first if

• You take levothyroxine. NIH notes that taking them together can noticeably reduce its effect, so you need to space them apart.
• You take a proton pump inhibitor. With less stomach acid, people on these often don't respond well to iron tablets.
• You take tetracycline or quinolone antibiotics, or levodopa. Iron binds to these in the gut and reduces how much you absorb.
• You're pregnant or breastfeeding. Your needs rise steeply, but your pregnancy care team should set the dose.
• You have coeliac disease or inflammatory bowel disease, or you've had stomach or bowel surgery. Absorption is affected and the cause needs looking into.
• You give blood regularly. Regular donation runs down your stores, so it's worth keeping an eye on.
• You take calcium supplements, or have tea, coffee or wine with meals. All of these reduce absorption, so spacing matters.
• You already take a multivitamin. Check whether it contains iron first.

• Ferrous sulfate. Best known for: The standard iron salt, and the one most trials compare against. Absorption: It is 20 per cent actual iron by weight, so 100 mg of the salt gives you about 20 mg of iron. Typical use: Tablets. It is also the form most of the evidence on gut side effects comes from, and the one people most often give up on.
• Ferrous fumarate. Best known for: The most actual iron of the common salts, so you need fewer milligrams of compound. Absorption: 33 per cent actual iron by weight. Typical use: Tablets and combination products, where tablet size matters.
• Ferrous gluconate. Best known for: Gives a low dose of actual iron for its weight, which is why it is used in liquids. Absorption: 12 per cent actual iron by weight, the lowest of the three classic salts. Typical use: Liquid iron tonics and lower-strength tablets, often taken in split doses.
• Iron amino acid chelate. Best known for: The wording most often printed on Australian labels, where the actual iron is listed separately. Absorption: The rules cap iron at 25 per cent of the chelate, so the compound weighs several times as much as the iron in it. Typical use: Modest doses of actual iron. It is presented as gentler, though the evidence comparing how well it is tolerated is limited.
• Iron bisglycinate (ferrous bisglycinate). Best known for: A specific glycine chelate, with its own Schedule 1 entry rather than counting as a general chelate. Absorption: The idea is that two glycine molecules shield the iron from blockers such as phytate. Human evidence comparing it with other forms is thinner than the marketing suggests. Typical use: Lower doses of actual iron, and the form most often chosen after a stronger salt did not agree with someone.
• Iron polymaltose. Best known for: An iron–carbohydrate complex (non-ionic) rather than a simple salt, familiar from pharmacy brands. Absorption: The iron is held inside a polymaltose shell, so less free iron is released in the gut. Typical use: Not available in Australian listed complementary medicines. It is not on Schedule 1, so products containing it have their own ARTG registrations.

Reference values. The NHMRC Nutrient Reference Values set the iron RDI at 8 mg a day for adult men of all ages, 18 mg a day for women aged 19–50 and 8 mg a day for women 51 and over. In pregnancy it's 27 mg a day, and 9–10 mg while breastfeeding. For younger ages: 9 mg (1–3 years), 10 mg (4–8), 8 mg (9–13), 11 mg for boys 14–18 and 15 mg for girls 14–18. The Adequate Intake for babies is 0.2 mg a day up to six months and 11 mg from seven to twelve months.

Typical supplemental range. Australian over-the-counter products stay under the 24 mg limit, and most single-ingredient tablets provide 5 mg to 24 mg of elemental (actual) iron. Liquid tonics are lower again per dose. Always compare the elemental iron figure, never the milligrams of the compound, because 24 mg of iron and a 24 mg tablet of an iron salt are not the same thing.

Upper level. The NHMRC Upper Level of Intake is 45 mg a day for adults, and much lower for children. Better Health Channel says that for children "20 mg per day is the safe upper limit", while noting "most iron supplements contain around 100 mg per tablet". That's why iron is a leading cause of accidental poisoning in children.

Worth knowing. Doses used to correct a diagnosed deficiency are above the over-the-counter limit and should be managed by your doctor. The number that tells you whether any of this applies to you is a ferritin result, not a milligram figure. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Oysters, cooked: about 8 mg per 85 g serve: haem iron, the most readily absorbed
• Beef liver: about 5 mg per 85 g serve
• White beans, canned: about 8 mg per cup: non-haem, so pair with a vitamin C source
• Lentils, boiled: about 3 mg per half cup
• Tofu, firm: about 3 mg per half cup
• Broccoli: cooking changes the maths: about 6 per cent of the iron is absorbed from raw broccoli, against 30 per cent from cooked

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• You have haemochromatosis or another iron-overload condition. Don't take it, because your body cannot get rid of extra iron.
• You have repeated blood transfusions. Don't take it unless a specialist tells you to.
• Children. Never give iron without a doctor's direction. An overdose can cause death (Better Health Channel).
• You think a child has swallowed iron. This is an emergency: call the Poisons Information Centre on 13 11 26.
• You want to treat tiredness yourself without a blood test. healthdirect says an iron study is the only reliable test.
• You take levothyroxine. Taking iron at the same time can noticeably reduce how well it works (NIH).
• You take proton pump inhibitors (reflux medicine). Less stomach acid means you absorb less iron and respond less well.
• You take tetracycline or quinolone antibiotics, or levodopa. Iron binds to them in the gut.
• Calcium supplements, tea, coffee, wine and phytates in wholegrains. All of these reduce how much iron you absorb.
• Pregnancy and breastfeeding. Your antenatal team should set the dose.
• You have coeliac disease or inflammatory bowel disease, or have had gut surgery. Absorption is affected, so the cause needs investigating.
• You give blood regularly. Your iron stores run down, so have them monitored.
• Constipation, nausea, vomiting, diarrhoea and dark stools are common effects (Better Health Channel).
• 45 mg a day or more brings more gut side effects (NIH). It is also the NHMRC Upper Level for adults.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.