Iron is a mineral required for human life. It sits at the heart of the hemoglobin molecule, which allows blood cells to carry oxygen from the lungs to the rest of the body. There are trace amounts of iron in unrefined salt, which lend both color and flavor, and in it’s own subtle way, perhaps a bit of nutritional balance as well.
Some people have posited that high iron levels in the blood will increase the risk of disease. According to the National Institutes of Health, the scientific jury is still out on that one. Nonetheless, some of these people worry to the point that they look even to the fringes of their diet, to the food they eat in in only small quantities–and there they find occasion to continue their fretting. Their concern is over unrefined salt. Can eating unrefined salt actually increase iron intake to a threatening level? A fair question. Let’s do the math:
The USDA’s recommended daily allowance (RDA) of iron is 18mg. But dietary iron comes in two different forms: heme and nonheme. Unrefined salts contain non-heme iron, which is not absorbed into the body as efficiently as heme iron.
|Some Reference Foods||mg Iron||RDA|
|1 cup lentils (cooked)||6.6||37%|
|1/2 cup Tofu||3.4||19%|
|Whole wheat bread (1 slice)||0.7||4%|
The RDA for salt intake is 2,300mg of sodium (Na), or about 6,100mg of NaCl (refined salt). Around the world, many people eat twice that amount of sodium.
So, what is the impact of salt consumption on you iron intake?
Himalayan salt, commonly singled out from the thousands of unrefined salts of the world as an example of a natural salt with its fair share of trace minerals, has 38.9 parts per million iron. Very roughly, the salt is about 0.00389% iron by mass.
Nutritionally speaking, a teaspoon of salt has the full U.S. RDA of sodium and 1.32% of a day’s supply of Iron:
|Himalayan Salt||mg of Salt||RDA of Salt||mg Iron|
If you ate two times the US maximum recommended amount of salt you would be consuming iron equivalent to what you’d get in 3/4 a slice of whole wheat bread or 1 heaping tablespoon of cooked lentils.
How much salt would you need to consume to pump your body up with the full U.S. RDA of Iron? 76 heaping teaspoons, or more salt an average salt-loving person consumes in a month. From a physiological standpoint, even that wouldn’t quite get you there, as the non-heme iron in the salt would not be efficiently absorbed. In sum, don’t look to salt to sort out your anemia.
From what I read, the scientific community is nowhere near a consensus on the real risk of high iron levels and increased risk of heart attack–in fact, from what I DON’T read (because there isn’t that much out there to read) it seems the scientific community has other fish to fry. But either way, I’m not enough of a lentils fanatic to lose much sleep over it in my own dietary contemplations. While noting the inconclusiveness of scientific knowledge at present, the US Government has kindly established the “tolerable upper intake level” of iron at 45mg per day. To get that much iron from salt you’d need to consume 190 heaping teaspoons of salt in a day, or 1,156,812mg.
That’s 2.55 pounds to you non-metric folks.