Chapter 10: Major minerals

03/28/2025- Started flashcard set ~X

Minerals are also known as?

Elements

What are overall characteristics of minerals?

• Minerals are inorganic nutrients that are essential to human health. Must be consumed in diet.

• Simplest nutrients, inorganic (no carbon), micronutrient (mg or mcg).

• Provide no energy: 0kcal/g

• The amount of each mineral found in our bodies vary greatly and therefore, so does consumption of those minerals.

• Major minerals= required in amounts larger than 100 mg.

• Minor or trace minerals= required in less than 100mg/day.

Which minerals are major minerals?

• Sodium

• Potassium

• Chloride

• Calcium

• Phosphorus

• Magnesium

• Sulfur

Which minerals are trace (minor) minerals?

• Iron

• Copper

• Zinc

• Selenium

• Iodine

• Chromium

• Fluoride

• Manganese

• Molybdenum

Which is the most abundant mineral in the human body?

Calcium

Which is the second most abundant mineral in the human body?

Phosphorus

Which is the third most abundant mineral in the human body?

Sulfur

What are the general functions of major and trace minerals?

• Fluid balance- sodium, chloride, potassium, phosphorus, and sulfur.

• Co-factors (energy metabolism)- Copper, chromium, manganese, and molybdenum.

• Antioxidants- Copper, zinc, and selenium.

• Structure (bones)- Calcium, phosphorus, magnesium.

• Part of hormones- Iodine

• Growth and repair- Zinc

• Blood components- Iron

Where does sodium come from?

• ~15% added by individuals

• ~10% naturally occurring in foods

• ~75% added by food manufacturers

Sodium:

• Table salt (NaCl): 40% sodium, 60% chloride

• Major cation (+ ion), extracellular fluid

Chloride:

• Table salt

• Major anion (- ion), extracellular fluid

Where can potassium be found?

• Fruits, vegetables, milk, grains, meats, dried beans.

• Major cation (+ ion), intracellular fluid.

Where can phosphorus be found?

• Dairy and meats

• 20-30% from food additives

  • Soda contains phosphoric acid

• Difficult to limit intake

Where can sulfur be found?

• Food proteins

• Acid-base balance function

• Component of body protein

Antioxidants

• Selenium is a key component of the enzyme glutathione peroxidase.

• Glutathione peroxidase neutralizes peroxides so they cannot form free radicals

• Copper and Zinc are key components of the antioxidant enzyme superoxide dismutase.

Which minerals support structure (bones)?

• Calcium

  • Makes up 40% of all the mineral present in the body.

  • Has many functions in addition to bones.

• Magnesium

  • Plant products: legumes, seeds, nuts, whole grains, vegetables.

• Fluoride

  • Toothpaste, tea.

• Phosphorus

  • Grains, proteins, dairy, packaged foods.

Mineral bioavailability

The degree to which the amount of the ingested mineral is absorbed and available to the body.

Which factors influence bioavailability?

• Plant-based foods often contains factors that decrease absorption including:

  • Oxalate and phytate that bind to minerals and inhibit their absorption.

• Minerals are better absorbed from animal-based foods.

• Varies with intake of other minerals and vitamins.

  • Enhance absorption

    • Vitamin C boosts iron absorption.

    • Vitamin D boosts calcium and magnesium absorption/

  • Reduced absorption

    • Excess Zinc in the diet can impair iron and copper absorption.

    • Calcium in the diet impairs iron absorption.

• Certain GI disorders and diseases such as Crohn’s disease, kidney disease, and aging processes may impair mineral absorption, increasing the risk of deficiencies.

How are minerals digested and absorbed?

• No enzymes necessary

• Minerals do not need to be digested

• Absorption rates depend on several factors:

  • Ionic form (some minerals carry different charges)

  • pH

  • Presence of other compounds

• Most absorption occurs in the small intestine, some absorption in large intestine.

What are some good sources of sodium? What are the recommended intakes? What happens in cases of toxicity?

Good sources include:

• Processed foods

• Table salt

• Pork

• Chicken

Recommended intakes for adults:

• <2,300 mg/day (UPPER LIMIT)

• ideally 1,500 mg/day

In cases of toxicity, can cause:

• High blood pressure

What are some good sources of potassium? What are the recommended intakes? What happens in cases of deficiency? What happens in cases of toxicity?

Good sources include:

• Fruits

• Vegetables

• Legumes

• Whole grains

• Milk

Recommended intakes:

• 4,700 mg/day (NO UPPER LIMIT)

In cases of deficiency, can cause:

• Irregular heartbeat

• muscle cramps

In cases of toxicity, can cause:

• Abnormal heartbeat

What are some good sources of chloride? What are the recommended intakes? What happens in cases of deficiency? Which groups are at risk? What happens in cases of toxicity?

Good sources include:

• Table salt

• processed foods

Recommended intakes are:

• <3,600 mg/day (UPPER LIMIT)

• 2,300 mg/day ideally

Deficiency of this mineral is unlikely, therefore there are no groups at risk nor any repercussions in cases of toxicity.

Calcium

The most abundant mineral in the body and greater than 99% is stored in bone tissue. Only 1% is found in the blood and soft tissues.

Calcium’s functional roles

• Bone and tooth formation

• Nerve impulse transmission

• Muscle contraction

• Blood clotting

• Without this mineral, the hormone insulin would not be released from cells in the pancreas and glycogen could not be broken down in muscle cells and used to provide energy for muscle contraction.

Bone mass and osteoporosis

• Peak bone mass: ages 20-30

• Bone loss begins at: ages 30-40

• Significant loss at menopause

• High risk for poor bone structure:

  • Females

  • Smaller framed individuals

  • Old age

  • Low calcium intake

  • Smoking

  • Eating disorders

Calcium homeostasis

• Blood calcium levels are closely regulated

• Hormones that regulate calcium levels are parathyroid hormone (PTH), calcitriol, and calcitonin.

When blood calcium levels drop, what happens internally?

• PTH is secreted by the parathyroid gland to increase blood calcium levels; PTH uses three mechanisms to increase blood calcium levels.

  • PTH stimulates the release of calcium stored in the bone.

  • PTH acts on kidney cells to increase calcium reabsorption and decrease its excretion in the urine.

  • PTH stimulates enzymes in the kidney that activate vitamin D to calcitriol.

• Calcitriol is the active hormones that acts on the intestinal cells and increases dietary calcium absorption.

When blood calcium levels are high, what happens internally?

• Hormone calcitonin is secreted by certain cells in the thyroid gland and PTH secretion stops.

• Calcitonin lowers blood calcium levels by increasing calcium excretion in urine, preventing further absorption in calcium in the gut and by directly inhibiting bone resorption.

Calcium absorption

• Enhancers

  • Vitamin D, stomach acid

• Inhibitors

  • Plant based phytates, oxalates, tannins

Veganism and Calcium

• Difficult to meet needs without dairy foods.

• Some plant sources of calcium are poorly absorbed.

• Choose fortified foods

  • Dairy substitutes

  • Tofu (some types)

  • Some RTE cereals, snacks

  • Some green leafy veggies

Other health benefits of calcium in the body

• Higher intakes of calcium decrease colon cancer risk and may suppress the growth of polyps that often precipitate cancer (The National Cancer Institute)

• Higher calcium consumption reduces blood pressure.

• High-calcium diet blocks kidney stone formation. Calcium inhibits the absorption of oxalate, a chemical in plants such as parsley and spinach, which is associated with an increased risk for developing kidney stones

  • Calcium’s protective effects on kidney stone formation occur only when you obtain calcium from dietary sources.

  • However, calcium supplements may actually increase the risk for kidney stones in susceptible people.

Groups at risk for calcium deficiency

• Adolescent teens

• Amenorrheic women and the “female athlete triad”

• Postmenopausal women

• The elderly

• Lactose-intolerant people

• Vegans

• People with milk allergies

Which calcium supplements should be bought?

• Supplements are sold primarily as calcium carbonate, calcium citrate. calcium lactate, and calcium phosphate, with elemental calcium contents of about 200 mg per pill.

• Note that calcium carbonate requires an acidic environment in the stomach to be used effectively.

  • May be a problem for those on medication to reduce stomach-acid production or for the elderly who may have a reduced ability to secrete acid in the stomach.

  • For these people, calcium citrate may be the better choice.

• The body is capable of absorbing approx. 30% of the calcium from these forms.

• Beware of lead.

What are good sources of phosphorus? What are the recommended intakes? What happens in cases of deficiency and toxicity? Which groups are at risk?

Good sources include:

• Salmon

• Yogurt

• Turkey

• Chicken

• Beef

• Lentils

Recommended intakes:

• 700mg/day ideally

• 3,000mg UPPER LIMIT

In cases of:

• Deficiency: Bone loss, weak bones

• Toxicity: none

Groups at risk:

• Older adults

• Alcoholics

What are the major functions of phosphorus?

• Structural component of bones, cell membranes (phospholipid bilayer), DNA and RNA, and ATP.

What are some good sources of sulfur? what are the recommended intakes? What happens in cases of deficiency and toxicity? Which groups are at risk?

good sources include:

• Protein foods (component of amino acids)

Recommended intakes:

• None specified

In cases of:

• Deficiency: Nothing when protein needs are met

• Toxicity: Nothing

Groups at risk:

• None

What are the major functions of sulfur?

• Comprises structure of some vitamins and amino acids

• Acid-base balance

• Part of hair and nails

• Important in the synthesis of insulin and heparin

What are some good sources of magnesium? What are the recommended intakes? What happens in cases of deficiency and toxicity? Which groups are at risk?

Good sources includes:

• Whole grains

• legumes

• Almonds

• Cashews

• Hazelnuts

• Beets

• Collard greens

• Kelp

Recommended intakes:

• 420 mg/day ideally

• 350 mg/day UPPER LIMIT

In cases of:

• Deficiency: Tremors, muscle spasms, loss of appetite, and nausea.

• Toxicity: Nausea, vomiting, low blood pressure.

Groups at risk:

• Alcoholics

• Individuals with kidney and GI disease

What are the major functions of magnesium?

• Component of mineralized bone

• ATP synthesis and utilization

• Carb, lipid, protein, RNA, and DNA synthesis