It’s Elemental

Iron is one of the most abundant metals in the world, comprising 5 percent of the earth’s crust, 80 percent of its core, and approximately 3 to 5 g of an adult’s body weight. Iron is the most abundant trace element in the body, and about 70 percent of it is found in the blood.

Iron is also stored in muscle fibres and tissues, where it helps with oxygen storage and metabolic processes. The remaining iron is stored as ferritin in the liver, in bone marrow, and in macrophages (a type of white blood cell).

This mineral is necessary for cell division, energy production, and oxygen transport, and is therefore indispensable. Yet, too much iron can lead to free radical production that can damage cells and tissues, so iron levels must be tightly regulated.

Iron deficiency is the number one diet-related health problem worldwide, with vegetarians more likely to be affected. Iron is available from heme (meat) or nonheme (plants) sources, though heme iron has higher bioavailability than nonheme iron. A typical diet provides approximately 15 to 20 mg of iron, but we’re only able to absorb about 1 to 2 mg.

There is no mechanism in the body to excrete excess iron, though most adults have little risk of overload from dietary sources. Hemochromatosis, an inherited disorder in which people overabsorb iron, can lead to conditions such as arthritis, cancer, cirrhosis of the liver, heart failure, and skin pigmentation.

Check with your health care practitioner if you suspect you’re deficient in iron.

News from the lab

• Iron supplements improve the performance of athletes who are iron deficient, but not in those athletes without deficiency.
• Iron supplementation in anemic children resulted in higher cognitive scores, increased stature, and improved weight-for-age outcomes.
• Having an adequately diversified dietary intake combined with iron and folic acid supplementation in pregnancy was associated with reduced occurrence of pre-eclampsia or eclampsia. Talk to your health care practitioner if you are pregnant.
• Toxins in the environment such as polychlorinated biphenyls (PCBs) may interfere with iron metabolism, influence iron homeostasis, and potentially force a supply of iron into tissues, including tumours.

Bone up on calcium

Calcium is often linked to bone health, and about 99 percent of the calcium in our body is stored in our bones. While it’s true that calcium helps keep bones strong, this mineral is also required for blood clotting, nerve signal transmission, hormone release, and maintaining a regular heartbeat.

About 30 percent of the calcium we eat is absorbed in the gut. Calcium is absorbed through an active transport process in the duodenum that can get overwhelmed at high concentrations of calcium. In other words, when supplementing with calcium, take no more than 400 to 500 mg, once or twice daily to maximize absorption. At menopause, women require more calcium, because lower estrogen levels promote bone resorption or breakdown.

News from the lab

• Women who meet the recommended dietary allowance (RDA) for calcium and magnesium have a reduced risk of metabolic syndrome, but men may require calcium intake that is higher than the current RDA to experience the protective effects.
• Menopausal women have reduced fracture risk when they take calcium along with vitamins D and K2.
• Calcium increases fat oxidation after a single meal and over several meals of the day, and modestly increases the amount of fat excreted from the body.

Multitasking magnesium

This mineral often gets lumped with calcium in the research, but magnesium has important jobs of its own. A cofactor in more than 300 enzyme systems, magnesium participates in blood pressure regulation and blood glucose control, as well as blood pressure regulation and bone strength.

By helping to transport calcium and potassium ions across cell membranes, magnesium impacts the conduction of nerve impulses, muscle contraction, and heart rhythm. Approximately 52 percent of magnesium is stored in bone, and the remainder is found in muscle and soft tissue, serum, and red blood cells.

Research links low magnesium levels with prediabetic conditions and type 2 diabetes as well as migraine headaches. Food sources of magnesium include spinach, beans, salmon and halibut, and nuts and seeds. Excess magnesium from food is excreted through the urine, but too much supplementary magnesium can cause diarrhea.

News from the lab

• Marginal to moderate magnesium deficiency is associated with chronic low-grade inflammatory stress, and is therefore a factor in cardiovascular disease and type 2 diabetes.
• Randomized controlled trials have shown that supplementing with 250 mg daily (women) and 365 mg daily (men) magnesium for three months reduced insulin resistance.

Secrets of silica

Until the 1970s, scientists did not believe that silicon was an essential nutrient for humans, and to this day we know more about what happens when it is absent than how it works in the body.

No daily reference intake has been established, but deficiency has been linked with malformations of the skull, peripheral bones, and joints as well as reduced collagen in the femur and vertebrae. Orthosilicic acid is the most bioavailable form of this mineral, and it has been found in tissues including the aorta, bone, kidneys, and liver.

Silica may also support the inflammatory response and help with the assimilation of other minerals. Stay tuned for more information about this mineral as its secrets are unearthed!

Some other important minerals

Potassium

Important to the function of our nerves and muscles together, potassium is also important in controlling blood pressure by helping to flush excess sodium.

Sources: dried prunes and raisins; beans and lentils; most fruits (bananas, oranges, and papayas); vegetables (particularly dark leafy greens, winter squash, and sweet potato); and sunflower seeds

Phosphorus

Making up about 1 percent of our body weight, the main function of phosphorus is in the formation of our bones and teeth.

Sources: potatoes (with skin); mushrooms; whole grains; cheese, yogurt, and milk; lean red meat; poultry; seafood; and shellfish

Zinc

Found in cells throughout the body, zinc supports the immune system to fight bacteria and viruses and to help heal wounds. It also helps our body use carbohydrates, protein, and fat.

Sources: lean red meat, poultry, beans and lentils, seeds and nuts, and shellfish (particularly oysters)

Selenium

Essential for many important functions in our body, selenium plays an important role in reproduction, thyroid metabolism, DNA synthesis, and protection from oxidative damage and infection.

Sources: mushrooms; couscous; brown rice; yogurt, cheese, and milk; nuts (particularly Brazil nuts); eggs; sunflower seeds; oysters and fish; and poultry