Are There Dangerous Amounts of Iron in Salt?

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
1 teaspoon 6,100 100% 0.23729
2 teaspoons 12,200 200% 0.47458

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.

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11 Responses to “Are There Dangerous Amounts of Iron in Salt?”

  1. on 13 Apr 2012 at 6:01 amGina Stipo

    It’s unfortunate that people continue to be afraid of getting nutrients, taking advice from doctors and the FDA who know little to nothing about nutrition. With the widespread level of iron-deficient anemia in western society, and considering how difficult it is for the body to absorb iron, everyone should look at iron-rich salts as a health benefit, and be encouraged to add them to their diets.

  2. on 31 May 2012 at 8:22 pmbob smith

    what effect does hemalayan salt iron have on hemochromatosis?i

  3. on 05 Jul 2012 at 12:50 pmMark Bitterman

    @Bob Smith – We aren’t medical professionals, so we can’t be sure what the effect is. But as we’ve outlined above, very, very little of our dietary iron comes from salt.

  4. on 06 Apr 2013 at 10:10 amAnonymous

    Your math is so far off that I find the credibility of your website to be rushed rather than thoroughly fact checked.
    76 teaspoons at .24% DRA of Iron is nowhere near 100%
    It’d be much closer to 416.667 teaspoons of salt to reach the DRA of Iron, but only if the rest of your math is correct.

  5. on 16 Apr 2013 at 4:55 pmMark Bitterman

    Thanks for catching that! The error was stating that a teaspoon of salt has 0.24% DRA. It is in fact 1.32%. The article has been corrected.

  6. on 06 May 2013 at 6:53 pmSteve

    So, basically, what you are saying is that the iron that gives Himalayan salt it’s color and is one of the highest trace minerals in Himalayan salt, is negligible as a nutrient. So, what is the point of using Himalayan salt in the first place? You would get the equivalent iron from 3/8 of a slice of bread. It also has trace Plutonium. That can’t be good.

  7. on 07 Jun 2013 at 8:09 amChristian S.

    Thank you for your informative posts on Himalayan Crystal Salts. What I find somewhat disconcerting, and of much more concern than the iron content, is the amount of aluminium (0.661 ppm) in the Himalayan salt. Aluminium has been linked to Alzheimer’s Disease, ALS and other degenerative diseases, as well as cancer (especially from the use of deodorants containing aluminium). Also, aluminium is not easy to get out of the body once it’s in, particularly for older folks with somewhat decreased glutathion levels, i.e. diminished detox ability.
    Do you have any information on the acceptable levels of aluminum?

  8. on 13 Aug 2013 at 3:48 pmMary Kanda

    Christian, thanks for your question, I’m eagerly waiting a response. I just looked at the aluminum content of Redmond Clay (presumably from the same mine as RealSalt in Utah) and it is the highest ranked element at 77,500 ppm. I don’t know what a ppm is but I certainly balk at using this clay for facials, toothpaste and baths. I’m going to write the company and see what they say. Very disappointing as I was hoping to get quality local bath and food salts.

  9. on 05 Dec 2013 at 5:59 amami

    ppm=parts per million. So it has 77,500 parts aluminum for every 1,000,000 parts in total. There are 922,500 parts of other things.

    In other words the Redmond Clay is 7.75% aluminum.


  10. on 11 Jan 2014 at 12:10 pmfran

    Ppm stands for parts per million

  11. on 12 Mar 2014 at 11:59 amJoseph

    @ Mary Kanda: A single PPM is roughly equal to one drop of water in a 35 gallon bathtub that is filled to the top. Using the same comparison, the clay you use is like 2.8 gallons of aluminum for the entire tub. I’m not really surprised, since aluminum is one of the most abundant elements (and the most abundant metal) in the Earth’s crust. I also don’t think you have anything to worry about using the clay topically (since it draws impurities and toxins out of the skin) or even using it in toothpaste. That being said, I don’t cook on aluminum cookware, limit aluminum foil use and I don’t use aluminum antiperspirants.

    @ Christian S.: As far as the aluminum content in salt, I wouldn’t be alarmed. That’s a little over one half of a drop in a full bath tub of water (using your .661 ppm figure). Aluminum is not highly toxic. I think that has something to do with our evolutionary/biological history coupled with the fact that aluminum is such an abundant element. Aluminum is also highly reactive and you’re not going to find elemental aluminum in your salt. It will be aluminum oxide or in silicate form and/or combined with other elements like calcium or magnesium.

    There is really no scientific/medical consensus regarding aluminum and Alzheimer’s. Still, it does make sense to limit exposure to consumed aluminum. It’s best to be safe than sorry since it has no known biological function in our bodies.

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