by Cat, July, 2007; Updated Aug 2017 re: “chew chew chew” for mineral absorption; updated May 2019; updateOct 2019, re: iodine, sources to avoid
What is a mineral, from a nutrient perspective? Wikipedia (6C) states, “As a group, minerals are one of the four groups of essential nutrients, the others of which are vitamins, essential fatty acids, and essential amino acids.” Nutritional minerals fall into three categories: Essential, Essential Trace, and Toxic Minerals (see chart below for which minerals fall into which category). Note that some minerals in the “toxic” category can be essential at trace levels (if bound or chelated by amino acids/proteins), but toxic in salt form; for example, selenium.
We get our minerals from the food we eat/drink: eating plants, animal meats and organs; and drinking water. We can also get them from eating soil (as a toddler, I used to pull up carrots and radishes to eat them, including the soil that came up with them).
- Includes: 1. Essential, Trace, and Toxic Heavy Minerals; 2. Common Food Sources of Essential and Trace Minerals; 3. Mineral Function; 4. Mineral Absorption: Tips to Improve
- See also: 1. Diet and Health Menu; 2. Magnesium (About); 3. Magnesium Chloride, 80% Solution; 4. Toxic Heavy Metals (About) < links to_HeavyMetals (iWeb)
Update links to (_HeavyMetals) when moved fro iWeb (a little more than half-way down). Also update link to _Heavy Metals, about 1/6 of the way down.
Minerals, in relation to human biochemistry, fall into three main categories, with the most common of each shown in the following table:
Details about each category
For more on essential and trace minerals, visit Weston A. Price Foundation’s “Mineral Primer” (2B).
- Essential Common Minerals: Our bodies need certain minerals for proper functioning of enzymes, co-enzymes, nerve impulses, bone tissue, etc.. The most common of these essential minerals are needed in significant quantities in our daily diet.
- Essential Trace Minerals: In addition to the common minerals, we also need trace amounts of other minerals known as trace minerals. (Of these trace minerals, some, such as copper, are required in trace amounts, but are toxic at even slightly elevated levels).
Of these, zinc, copper and selenium are important for brain health; magnesium and potassium are important for muscles. (1D
Note that while Selenium is an essential trace mineral, in the wrong form, it is a toxic heavy metal. Sodium selenite is a toxic form found in some multis (like Centrum) and most pet food. The safe forms are when it is bound to (chelated by) a protein or amino acid. Selenium yeast (nutritional yeast grown on selenium) is one safe version.
- Toxic Heavy Metals: (No, not a type of rock band). These minerals are toxic, no matter what the level. Most heavy metals are not an issue, because our chance of exposure is very small. But some of these toxic minerals (such as aluminum, lead and mercury) have a high chance of exposure and are causing health problems. (1A). Aluminum or mercury are found in vaccines as an adjuvant (makes the vaccine more effective, but is also toxic).
Toxic heavy metals are discussed in much more depth in a series of articles on my iWeb site (which will eventually be moved to a blog). In the meantime see the introductory article which includes links to the other articles in the series: Heavy Metal Toxicity Menu. < update link when these are moved to a blog.
Common Food Sources of Essential and Trace Minerals
Back when I first started writing this article, I found several sites that had useful information about minerals, including:
- recommended daily intake;
- dietary sources;
- deficiency symptoms;
- things that inhibit and enhance absorption
Those sites are listed at the bottom of this article, as bulleted items below the numbered references. Unfortunately, most of those links (including the best of the bunch, The Herb Shop) are no longer valid. I am working on finding new links to replace them. Meanwhile, here’s what I saved from those articles for each mineral in alphabetical order:
- Boron (Trace): Fruits, vegetables**, nuts*, wine, cider, beer
- Chromium (Trace): Whole grain cereals*, clams, corn oil, brewer’s yeast
- Calcium (Essential): dairy products, canned salmon or sardines, shellfish, bone meal, liver, nuts* and seeds*, dark green leafy veggies **, and dolomite (caution: dolomite can be contaminated with heavy metals, so be sure your source is free of these)
Check out an interesting site concerning calcium supplementation from the University of Oregon (16). It gives a general discussion of which types of calcium are the best to take as supplement, and using your average urine and saliva pH to determine which type is best for you.
- Chloride (Essential): table salt, unrefined sea salt (such as celtic salt), seaweed, rye, tomatoes, lettuce, celery, olives
- Cobalt (Trace): Meats, leafy green vegetables**, fruits, poultry, milk, clams, organ meats, unrefined sea salt (such as celtic salt)
- Copper (Trace): Soybeans*, raisins, nuts*, bone meal, organ meats, fish, legumes*, molasses, unrefined sea salt (such as celtic salt). Along with zinc and selenium, copper is important for brain health. (1D
- Iodine (Trace): Mushrooms, iodized salt, fish, kelp and other sea vegetables; note that iodized salt and supplemental iodine (including multis that contain iodine) are not your best choice. See section on Iodine: What to Avoid, below (under NOTES).
- Iron (Essential): red meat, dark green leafy veggies**, fish (tuna, salmon), poultry, cherry juice, liver, eggs, dried fruits, legumes*, whole grains*, wheat germ*.
- Manganese (Trace): Whole grains*, nuts*, legumes*, leafy green vegetables**, bananas, celery, pineapple, liver, egg yolks, unrefined sea salt (such as celtic salt),
- Magnesium (Essential): molasses, honey, legumes*, tuna, bone meal, nuts* and seeds*, cocoa, whole grains*, dried apricots, dark green leafy veggies**, sea vegetables.
- Molybdenum (Trace): dairy products, legumes*, organ meats, grains*, unrefined sea salt (such as celtic salt).
- Nickel (Trace): Chocolate, nuts*, dried beans*, grains*
- Phosphorus (Essential): dairy products, legumes*, bone meal, nuts*, yellow cheese, eggs, fish, grains*, poultry.
- Potassium (Essential): meats, legumes*, whole grains,* bananas, potato skin, dried fruits, dates, figs, apricots, peaches, nuts*, seafood
- Selenium (Trace): broccoli, onions and garlic, tuna, herring, shellfish, calf’s liver and kidney, eggs, sunflower and sesame seeds*, brazil nuts*, mushrooms, bran* and wheat germ*, barley, brewer’s yeast, whole grain*, unrefined sea salt (such as celtic salt).
Along with zinc and copper, selenium is important for brain health. (1D
- Silicon (Trace): unrefined high-fiber grains*, cereal products*, root vegetables, unrefined sea salt (such as celtic salt)
- Silver (Trace): I could not find a list of dietary silver.
- Sodium (Essential): Table salt, sea salt, sea vegetables, olives, dairy products, dark green leafy veggies**.
- Sulfur (Essential): protein foods such as meat, eggs, legumes.
- Strontium (Trace): sea vegetables, bone meal, dark green leafy vegetables**, nuts* and seeds*, unrefined sea salt (such as celtic salt). Strontium and calcium are almost always found together in plant foods.
- Vanadium (Trace): extra virgin, unfiltered, olive oil, parsley, black pepper, dill, mushrooms and shellfish
- Zinc (Trace): red meat and shellfish, especially oysters, organ meats (such as liver), brewers yeast, fish, liver, spinach**, mushrooms, sunflower seeds*, unrefined sea salt (such as celtic salt). Animal sources appear to be better-absorbed than plant sources for most minerals, including zinc.
Along with copper and selenium, zinc is important for brain health. (1D
* Sprouting or presoaking legumes, nuts and whole grains makes their magnesium available for absorption.
** Add a little butter or olive oil to your dark green veggies: it helps to assimilate the magnesium.
*** Iodine: What to Avoid
- #1: Avoid foods that contain toxic fluoride and bromide that block iodine receptors on cells; this includes brominated flour (all non-Organic white flour) and fluoridated water or toothpaste containing fluoride. For more about the harm of brominated flour, see Healthfully article (18).
- #2: Avoid supplemental iodine; this is counterintuitive, but taking supplemental iodine can actually make thyroid function worse. See Dr. Alan Christianson’s article (19) for more detail. I’m not sure I agree with avoiding sea vegetables (whole food), because our hunter-gatherer ancestors sought them out, even if they didn’t live near the sea. Dr. Christianson advises the following (19):
- Avoid iodized salt
- Avoid sea vegetables
- Avoid all iodine supplements
- Avoid all supplements that contain iodine
- Avoid all commercial bread and baked goods
- Avoid or reduce dairy foods
Minerals are important for many functions in the body; for example,
- calcium gives strength to bone;
- iron enables haemoglobin to carry oxygen through the blood;
- magnesium helps muscles to relax.
But perhaps the largest function of minerals is their involvement with enzymes to cause or assist specific chemical reactions to happen, such as for protein synthesis, generation of energy for muscle contraction, nerve transmission or electrical impulses, etc.
In most, the metal must be in ionic (charged) form, to function in the body. For example, metallic iron (Fe) has no known bio-activity in humans (and has toxic activity in the body), but its two ionic forms (Fe+2 and Fe+3) are present in several enzymes and haemoglobin.
Every organ in the body needs minerals. Here’s a partial list I found on a Trace Minerals product site (13), to which I’ve added a few (this list is not complete):
- Thyroid needs iodine, selenium
- Adrenals need copper
- Blood requires iron and cobalt
- Brain requires phosphate and magnesium (14)
- Bones require calcium and magnesium
- Bowels need potassium
- Ligaments need manganese
- Liver needs selenium (9)
- Lymphatic system needs sulfur
- Immune system needs zinc
- Heart requires selenium
- Muscles (including those in your artery walls) need magnesium
Function of specific minerals
Magnesium is an essential component of many biological processes, and adequate magnesium in the diet improves calcium absorption. Dietary deficiency of magnesium has been implicated in many disorders including hypoglycemia, insulin resistance, asthma and bowel disorders, along with many others. See Mercola: The Miracle of Magnesium (1C) and Problems Due to Magnesium Deficiency (1C) for more. See also my posts on Magnesium (About) and Magnesium Chloride, 80% Solution (supplement).
An example of magnesium shortage: I had symptoms of a heart attack the night of Dec 23, 2010, but the symptoms faded so I didn’t go to hospital until the next day. Turns out, it wasn’t a real heart attack, but rather a condition called “vaso-spastic angina,” which means the muscles in the walls of the arteries went into a temporary spasm, blocking blood flow for less than a second. The most common cause of this condition is insufficient magnesium, which is essential for allowing muscles to relax. So I increased my daily dosage of magnesium chloride, and I have not had the problem again (as of this writing, May 2019).
Selenium is an essential component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defense systems, and immune function. Accumulating evidence indicates an inverse relationship between selenium intake and cancer incidence (as selenium intake goes up, cancer incidence goes down). Selenium is also important at the active site of many proteins (enzymes), including the antioxidizing enzyme glutathione peroxidase, important for liver’s detox function. And it works with vitamin E in many other antioxidant systems throughout the body (from World’s Healthiest Foods (1E)). Signs of selenium deficiency include: low thyroid; white vertical ridges on the finger nails as you age.
Green Med Info (20a) has an informative article that sites several studies: The Top 6 Benefits of Selenium (see the article for more detail):
- Antioxidant and Reduces Oxidative Stress;
- Boosts skin health;
- Benefits those with asthma by lowering oxidative stress;
- Helps prevent and improve health of those with thyroid disease;
- Promotes heart health
- Brain health, by slowing progression of dementia, and may help prevent Alzheimer’s.
Sulfur is essential for many body functions including involvement in electron transfer process for energy production in mitochondria; detox, especially as the metabolite glutathione, which is a storage form of sulfur; protein and enzyme integrity (sulfur bonds hold proteins’ shape); proper insulin function (sulfur bonds between protein chains). Most abundant food sources are fish and grass/pasture raised meats. See Mercola’s article on sulfur (1F) for more.
Zinc: I tend to have a shortage of zinc, probably because in general, I have trouble absorbing all minerals due to issues in my gut. I have learned how to tell when my zinc levels are low: little white clouds appear on my fingernails (not the white vertical lines, which is a sign of selenium deficiency). Another sign of zinc deficiency is loss of sense of smell. See Mercola’s article: Study warns that losing your sense of smell may mean you won’t live much longer (1E). I lost my sense of smell in 2014 and it is 2017 as I write this; my clock is definitely ticking.
Mercola writes, “Zinc, an essential trace mineral, is required to produce an enzyme called carbonic anhydrase (CA) VI, critical to taste and smell, which is why loss of sense of smell is one of the classic signs of chronic zinc deficiency.” It is also important for “strong immunity; important component of the enzymes involved in tissue remodeling and prevention of cancer; maintenance of your mood, mental clarity, and restorative sleep; prostate and intestinal health.” (1E)
Mercola suggests the “sniff therapy” to improve your sense of smell: Choose 3 or 4 different scents such as floral, fruity and coffee. Sniff them 4 – 6 times a day; This helps the different receptors in your nose to work better. Smelling your food before eating it to notice scent of flowers, cut grass or even rain may also help. (1E)
When eating a meal, one naturally assumes the body absorbs all the nutrients from the food. But, sadly, this is not the case. Minerals are amongst the hardest to absorb. For many of us, the minerals are eliminated in the feces. Over the eons of time, our bodies have learned how to maximize mineral absorption, by slowing down the movement of food through the gut, to give more time to work on pulling out the minerals. This slowing down results in constipation. So if you have trouble with constipation, it could mean that you are deficient in one or more minerals, especially magnesium.
Add to the problem of malabsorption, the general lack of good quality nutrients in our modern diet, and it is easy to see the many of us have health problems due to insufficient minerals.
Obviously, the first thing we can do is improve the quality of our diet by eating nutrient-rich whole foods, preferably organic. Consider that minerals from animal sources are better absorbed than those from plant sources; and that pasteurization makes many minerals unavailable for absorption (for example, calcium and magnesium in pasteurized milk). We could switch from commercial iodized salt to mineral-rich unrefined sea salt. We could also take mineral supplements, but, sadly, many of these are very poorly absorbed, or worse yet, contain a toxic form of heavy-metal minerals such as selenium.
The next thing we should do, is improve absorption of minerals from our diet. How to do this?
#1: Chew chew chew
Chewing activates secretion not only of saliva, but also hormones that trigger the digestive system to be ready for food. This improves the level of absorption of all nutrients, including minerals. The production of saliva triggers the stomach to start producing hydrochloric acid (HCl) to assist in digestion.
2017: I started an experiment because I take magnesium (MgCl2 solution) about 1 hour before breakfast, and again 3 – 4 hours after dinner (just before bed) when I don’t have food to chew, which means, my stomach acid is not high enough to support absorption of the magnesium. For the experiment, I take capsules of apple cider vinegar (ACV) with the mag solution, hoping that acid will help the low-HCL stomach to absorb the magnesium.
2019: I’ve been taking the ACV upon rising and before bed every day since I started, and I’ve not had any symptoms of magnesium shortage. This doesn’t confirm the helpfulness of the ACV, but at least it is not causing harm!
Hopefully I’ll remember to update this posting, regarding my experiment.
#2. Add fats to your diet
The minerals in foods, including fruits and vegetables are more easily absorbed if fat is present in the same meal. Indeed, this is the reason for adding salad dressings to a salad of mineral-rich green leafy vegetables. And its also a good reason to pass on ultra-lean meats, and seek out choice cuts marbled with fat. Or to spread some butter on your whole-grain bread.
How do fats improve mineral absorption? One way is by stimulating the stomach to secrete hyrdrochloric acid. This is a very strong acid and helps to liberate the minerals from the food.
#3. Ensure your gut has plenty of bifidobacteria (a type of probiotic).
A 2009 study in the Journal of Agricultural and Food Chemistry, October 9, 2009 (17) reports that Bifidobacteria produce a phytase enzyme that may help humans with mineral absorption by breaking down the phytates from dietary fiber, when the bifidobacteria are present in the gut. See my page: Probiotic Foods: Achieving Eubiosis for more. See also Probiotic & Prebiotic Supplements.
#4. Increase dietary inulin and FOS (fructo-oligosaccharides).
See Carbs: Inulin (a non-starchy carb) for more about these important carbs.
These fiber foods are fermented in the gut, and their fermentation raises the acidity of the gut, which increases absorption of minerals. It is the probiotic bacteria that do this fermentation, so it is a good idea to ensure your gut has plenty of these, by:
- drinking lacto-fermented beverages (kefir, kvass, natural ginger ale, etc.),
- eating lacto-fermented foods (lacto-pickled beets, sauerkraut, kimchi, etc.), and
- eating cultured dairy products (yogurt, kefir, buttermilk, cheese, etc.). (15)
Inulin is one type of FOS present in foods such as slow-roasted sweet potatoes, onions, and leeks.
#5 Sprout or soak
It is important to sprout or at least pre-soak whole grains, seeds and nuts before consumption. This process deactivates the phytates present in these foods. Phytates are naturally occurring substances in the bran of grains, seeds and some nuts, that have the unfortunate effect of blocking uptake of dietary essential minerals – calcium, magnesium, copper, iron and especially zinc – in the intestinal tract.
Sprouting takes it one step further, by starting the breakdown of toxic lectins in seeds. See Lectins: what they are, and how to deal with them for more.
Sprouting and soaking are traditional methods developed by traditional peoples to maximize nutrient absorption for optimum health. These methods include:
- Soaking of nuts, then roasting dry
- liming of corn (to make masa harina)
- sprouting of grains such as rye, oat, barley for use in cereals, breads, pasta
- slow-cooking of grains and legumes
Soy is especially problematic, as the bean contains unusually high levels of phytates that are resistant to traditional methods of deactivation.
#6. Increase your vitamin D
This vitamin is essential for mineral transport from the gut into the blood. There are two ways to increase this vitamin:
- Spend time in the midday sun (without using UVB blockers), because sunlight activates the conversion of cholesterol in the skin to vitamin D3, which is then absorbed into the blood.
- Supplement with vitamin D3, preferably as good quality cod liver oil. Make sure your supplemental form is natural D3, not synthetic D2. The vitamin D added to milk and orange juice is usually the synthetic D2 version, which is not as active as the natural D3, and is toxic at levels above about 200 IU per day (D3 does not have this toxicity; you can take 2000 IU per day of D3 without toxicity problems).
#7. Watch what you drink with your meals
Keep caffeinated and alcoholic drinks to a minimum at mealtimes, as both caffeine and alcohol interferes with mineral absorption. If you are iron deficient, avoid milk with your meals, as it interferes with iron absorption. On the other hand, freshly-squeezed orange juice is a good thing to drink with meals (but not as a screwdriver, since that contains alcohol), as the ascorbic acid enhances iron absorption. (Original link lost – was ’19’ but not the same as ’19’ in references list ).
Sweetened sodas are also not a good option to drink at any time. Sodas sweetened with high fructose corn syrup have devastating effects on health; sodas sweetened with the artificial sweetener aspartame over-excite the central nervous system and destroy brain cells; and the jury is still out on sucralose (splenda) as a soda sweetener. However, drinking “bitters and soda” does not have this problem (as long as the soda is not sweetened). See Digestive Bitters and Bitter Foods for more.
A good alternative to caffeinated, alcoholic and soda beverages are homemade kefir ‘sodas’ such as Kefir Ginger Ale. Ginger ale has the added benefit of being calming and soothing for the digestive system.
It is best to drink water a while before a meal, rather than with a meal. This is because the water dilutes the acidic secretions of the stomach, making them less effective.
- (1) mercola.com/2003/dec/27/toxic_metals.htm
- (15) articles.mercola.com/sites/articles/archive/2004/08/07/miracle-magnesium.aspx and
- (15) articles.mercola.com/sites/articles/archive/2017/09/06/magnesium-deficiency-effects.aspx
- (16) articles.mercola.com/sites/articles/archive/2017/08/13/heal-mental-disorders-with-nutrition.aspx
- (17) articles.mercola.com/sites/articles/archive/2014/10/15/anosmia-loss-sense-smell.aspx
- Weston A Price Foundation:
- (2) hbci.com/~wenonah/hydro/hg.htm#problem (link no longer valid)
- (3) emedicine.com/EMERG/topic813.htm or emedicine.medscape.com/article/1175560-overview
- (4) karlloren.com/ultrasound/p18.htm (link no longer valid)
- (5) Wikipedia:
- (6) eje-online.org/cgi/content/abstract/138/2/185 (link no longer valid)
- (7) jigsawhealth.com/articles/heavy_metal_toxicity.html (link no longer valid)
- (9) cf.ac.uk/biosi/staff/kille/Lecturers/metalsinbiology3/sld002.html link took me to cardiff.ac.uk/biosciences from where one must search for the particular lecturer
- (10) freepatentsonline.com/20050003047.html (link not secure)
- (11) Drinks to Maximize Vitamin Absorption – What to Drink with Meals: vitamindeals.info/articles/what-to-drink.html
- (12) ift.confex.com/ift/2004/techprogram/paper_25804.htm (link no longer valid)
- (13) mortersupplements.com/traceminerals1.html (link no longer valid)
- (14) ahealingplace.org/meditation/medbrainutrient.html
- (18) whfoods.com/genpage.php?tname=foodspice&dbid=127 (link no longer valid)
- University of Oregon: uoregon.edu/~sshapiro/Pemphigus/Supplements.html
- (21) ncbi.nlm.nih.gov/pubmed/19817458
- (new) drchristianson.com/another-reason-to-avoid-vitamins-with-iodine/
- Green Med Info:
The following links, “References for Food Sources of Minerals,” were not part of the numbered list, above on my old iWeb site, so I’ve given them bullets instead
- herbshop.com/minguide.htm (url no longer valid)
- original link: www.drdavidwilliams.com/c/thyroid_health_recs.asp cannot be found. So tried https://www.drdavidwilliams.com then searched for “thyroid health” but got a supplement that isn’t about thyroid health.
- answers.com/topic/dietary-mineral?cat=health (bad link)