Cast Iron Cookware and Iron: Does a Lohe Ki Kadai Add Iron?
Yes, cooking in a cast iron kadai or tawa does add some iron to food, and acidic, moist dishes simmered for longer pick up the most. But the amount of cast iron cookware iron that reaches your plate varies widely from pan to pan and dish to dish, and an iron kadai is a helpful kitchen habit, not a substitute for iron-rich food or for the treatment a doctor gives for anaemia.
The honest answer
- Does food gain iron? Yes, measurably, in most foods tested
- What raises it: acidity (tomato, imli, amchur), moisture, longer cooking time
- What lowers it: dry, quick cooking (roti on a tawa), a heavily seasoned old pan
- Anaemia: modest gains in some child trials; not a treatment on its own
- Care: dry at once, oil lightly, do not leave food standing in it
Does cast iron really add iron to food?
It does, and this is one of the few kitchen beliefs with decent lab evidence behind it. A well-known 1986 analysis in the Journal of the American Dietetic Association cooked twenty foods in iron and non-iron pots and measured the iron in each. Most of the foods held significantly more iron when cooked in iron. The same work pinned down why: acidity, moisture and cooking time all changed how much iron moved from the pan into the food. It also found that two different iron skillets gave different results, probably because of how much each had been used before.
That last point matters for anyone hoping for a precise number. There is no honest “X mg per meal” figure for a lohe ki kadai. A brand-new, rough kadai with a thin seasoning gives off more than a glossy, decades-old one. A tomato salan simmered for 40 minutes picks up more than a quick dry sabzi stirred for five.
Which desi dishes pick up the most iron?
| Dish type | Iron pickup | Why |
|---|---|---|
| Tomato or imli based salan, sambar, chana masala | Higher | Acidic, wet, long simmer |
| Daal, saag, khichdi | Moderate | Wet and cooked a while, less acid |
| Dry sabzi, bhuna, stir fries | Lower | Short time, little liquid |
| Roti or paratha on an iron tawa | Minimal | Dry, seconds of contact |
So the dishes where an iron pan helps most are also the ones that can taste slightly metallic or turn darker if left too long. Palak and other greens can look greyish after a long cook in iron. That is the iron reacting with plant compounds, not a sign of danger.
Cook in iron, serve in steel
Simmer your tomato or imli dish in the iron kadai, then move it to a steel or glass bowl as soon as it is done. You keep most of the iron the cooking added, avoid the metallic taste that builds when acidic food stands in iron for hours, and protect the pan’s seasoning at the same time.
Can an iron kadai help with anaemia?
Here the evidence is more mixed. A 2019 systematic review in PLoS One looked at eleven studies of iron pots and iron ingots in low and middle income countries. In half of the pot studies there was a significant rise in haemoglobin or iron measures, the other half did not. Results were better in children than in women, and they depended heavily on whether families actually used the pots every day. The authors called for more research on both how well it works and how safe it is long term.
A small Indian trial in preschool children found iron-rich snacks cooked in iron pots had more iron than the same snacks in non-stick pans, and the children’s haemoglobin rose over four months. A 2021 review of thirteen studies reached a similar “promising but more research needed” verdict.
Put plainly: an iron kadai can add a little iron to a family’s food over time. It will not correct a real deficiency on its own, and it cannot tell you whether you have one. That needs a blood test, and haemoglobin is only part of the picture; see our guide to ferritin vs haemoglobin.
An iron pan is a small daily nudge, not a prescription.
How to get more out of the iron you eat
- Pair with vitamin C. Tomato, lemon, amla, green chilli or fresh fruit in the same meal help the body take up plant iron.
- Move the chai. Tea and coffee with meals make it harder to absorb iron. Have chai an hour or so away from main meals.
- Build the plate. Daals, chana, rajma, leafy greens and meat if you eat it carry far more iron than any pan adds.
Seasoning and rust: keeping a lohe ki kadai usable
Seasoning a new or stripped kadai
- Wash with hot water and a little soap to remove factory coating. Dry completely on the stove for 2 minutes.
- Rub a thin layer of mustard or any cooking oil over the inside with a cloth. Wipe off the excess so it looks almost dry.
- Heat on medium for 10 to 15 minutes until it smokes lightly and darkens. Let it cool.
- Repeat 2 or 3 times. The first few dishes should be oily ones like frying or bhuna, not tomato curries.
Daily care
- Wash soon after cooking. A little soap is fine; avoid soaking for hours.
- Dry on the flame for a minute right away. Water left on iron rusts it overnight.
- Wipe a few drops of oil inside while it is warm.
- Store dry and uncovered or with a paper towel inside, not stacked wet.
Fixing rust
Light orange rust scrubs off with steel wool or a paste of salt and a little oil. Rinse, dry on the flame and re-season. Do not cook in a pan with flaking, crusted rust until it is cleaned back to bare metal and re-seasoned. Deep pitting means it is time to replace it.
For how iron compares with steel, non-stick and clay overall, see our cookware comparison, and for the aluminium question, aluminium utensils and the Alzheimer’s myth. More kitchen how and why is in our Kitchen Science, Honestly section.
Many grandmothers kept a lohe ki kadai for saag and a separate one for halwa, and some insisted that iron pots “make blood”. The pot part is backed by measurements; the “make blood” part is a simplification. Iron from a pan joins the iron in food, and the body still decides how much to absorb.
People with haemochromatosis, an inherited condition in which iron slowly builds up, or anyone told they have iron overload or need regular blood transfusions should ask their doctor whether to avoid iron cookware. If you have symptoms of anaemia such as tiredness, breathlessness on stairs, pale skin, or a racing heart, get a blood test rather than relying on a pan. Never stop or change iron treatment a doctor prescribed because you cook in iron. See a doctor urgently for chest pain, fainting or severe breathlessness.
Cast iron and iron in food: common questions
Does cooking in cast iron add iron to food?
Yes. Lab measurements show most foods cooked in iron pans contain more iron than when cooked in other pots. Acidic, moist foods cooked for longer pick up the most.
How much iron does a cast iron pan add?
There is no reliable single number. It depends on the dish’s acidity, water content and cooking time, and on how new and how seasoned the pan is. Measurements vary from barely any to a meaningful amount.
Is an iron kadai good for anaemia?
It may help a little as part of an iron-rich diet, especially in children, according to reviews of trials. It is not a treatment. Anyone who may be anaemic needs a blood test and their doctor’s advice.
Can I cook tomato in an iron kadai?
Yes, and it picks up more iron. Very long simmers or leaving the dish to stand can make it taste metallic and wear the seasoning, so transfer it to another bowl once cooked.
Why does my food turn black in an iron pan?
Iron reacts with compounds in some foods, such as greens and imli, and darkens them. It is not harmful, but cooking for a shorter time or moving the food out promptly keeps the colour better.
How do I season a cast iron tawa?
Wash, dry fully on the flame, rub a very thin layer of oil, then heat for 10 to 15 minutes until it lightly smokes. Repeat two or three times before first use.
How do I remove rust from a lohe ki kadai?
Scrub with steel wool or salt and oil until bare metal shows, rinse, dry on the flame straight away, then oil and heat to re-season.
Can I use soap on cast iron?
A little mild soap does not ruin a well-seasoned pan. Soaking it for hours or putting it in a dishwasher does. Always dry it on the stove and oil it lightly.
Is cast iron safe for everyone?
For most people, yes. People with haemochromatosis or iron overload should ask their doctor before cooking in iron regularly.
Does a roti tawa add iron?
Very little. Roti is dry and touches the tawa for seconds, so hardly any iron transfers. Wet, acidic dishes in a kadai are where the effect shows.
Sources
- PubMed 3722654: Brittin and Nossaman, Iron content of food cooked in iron utensils (J Am Diet Assoc, 1986)
- PubMed 31479458: Iron-containing cookware for iron deficiency anemia, systematic review (PLoS One, 2019)
- PubMed 23868537: Beneficial effect of iron pot cooking on iron status (Indian J Pediatr, 2013)
- PubMed 34290890: Iron-containing cookware and haemoglobin, systematic review (Nepal J Epidemiol, 2021)
- NHS: Iron deficiency anaemia (tea and coffee reduce absorption)
- NHS: Haemochromatosis