NDFS ch. 9 LO's minerals (+ notes)

how are minerals classified

• macrominerals = needed in large amounts (Ca, Na, K)

• microminerals (trace) = needed in small amounts (fe, Zn, Se)

what are the general roles of minerals

• bone foramtion (Ca, P, Mg)

• fluid balance (Na, K, Cl)

• enzyme function (Fe, Zn, Cu)

• nerve & muscle function

how can mineral deficiencies occur

• low intake

• poor absorption

• increased lossed (sweat, urine, menstruation)

• high exercise demands

how can mineral toxicities occur?

• excess supplementation

• high fortified food intake

• imbalance with other minerals

why are deficiencies harmful

• decreased performance (fatigue, weakness)

• impaired body functions (bone loss, anemia)

why are excesses harmful

• toxic effects

• interfere with absorption of other minerals

• can impair health

what increases bone mineral density

• weight-bearing exercise

• adequate calcium & vitamin D

• hormonal balance

what decreases bone mineral density

• inactivity

• low calcium intake

• amenorrhea/low energy availability

• aging

what minerals are important for bone?

• calcium

• phosphorus

• magnesium

• fluoride

why is BMD important for performance

• prevents fractures

• supports strength and movement

• low BMD → osteoporosis → injury risk

what is irons role in the body

• part of hemoglobin → carries oxygen

• essential for RBC production

what happens with low iron intake

• iron deficiency → anemia

• low oxygen delivery

how does low iron affect performance

• fatigue

• decreased endurance & aerobic capacity

who is at higher risk for iron deficiency

• female athletes

• endurance athletes

• those with low dietary intake

what role do minerals play in immunity

• support immune cell function

• help regulate inflammation

which minerals are important for immunity

• zinc → immune cell production

• selenium → antioxidant defense

• iron → supoorts immune signaling

what impairs immune function

• low zinc, magnesium, selenium

• excess zinc or iron

• heavy training stress

what are natural food sources of minerals

whole foods (meat, dairy, fruits, veggies, grains)

what are fortified/processed sources

minerals added to foods (cereal, juice, plant-based milks)

what are supplement sources

pills, powders, capsules

which source is best

food > fortified > supplements

why are supplements sometimes risky

• higher risk of toxicity

• can disrupt mineral balance

• not always necessary

whats the big picture of minerals

• needed for structure (bone), function (enzymes), and regulation (fluid balance)

• both too little AND too much are harmful

• key for performance, oxygen transport, and immunity

• best obtained through a balanced diet

what is the RDA for iron

• men & postmenopausal women: 8 mg/day

• Women (19-50): 18 mg/day

• Pregnant women: 27 mg/day

what is the UL for iron

40-45 mg/day

what are the two types of iron

• heme iron (animal foods, better absorbed ~30-35%)

• nonhdme iron (plant foods, less absorbed, more regulated)

what is the main function of hemoglobin

carries oxygen in the blood

what does iron do in the body

• helps transport oxygen

• exists in 2 oxidation states (must be tightly controlled 0 free iron is harmful)

where is most iron stored

in tissues as ferritin

what is ferritin

a storage protein that “traps” iron and reflects iron status

what does transferrin do

transports iron in the blood

what is transferrin saturation used for

detecting early iron deficiency

Where is iron found in the body (%)

• 66% hemoglobin

• 30% ferritin (storage)

• Small amounts

  • myoglobin (muscle oxygen)

  • transferrin (transport)

  • Chelatable iron (~1%)

what is hepcidin

a hormone from the liver that regulates iron absorption

what happens when hepcidin increases

decrease iron absorption

what happens when hepcidin decreases

increase iron absorption

what happens in stage 1 iron depletion

• low ferritin (<12 ug/L)

• no symptoms

what happens in stage 2 iron deficiency

• low ferritin + low transferrin saturation (<16%)

• symptoms: fatigue, cognitive issues

• hemoglobin still normal

what happens in stage 3 (iron-deficiency anemia)

• low ferritin +low transferrin + low hemoglobin

• Hb <130 g/L (men), <120 g/L (women)

what is sports anemia

diluted red blood cells (not true anemia)

why area athletes at risk for irion deficiency

• increased hepcidin from exercise

• foot-strike hemolysis (runners)

• hematuria

• Mentruation

• high altitude

• BI bleeding

• aspirin use

who is at high risk and may need iron supplements

• female distance runners

• heavy menstrual cycles

• vegetarians

• high-altitude athletes

• dieting athletes

how fast does iron deficiency recover, without supplements

slowly

what increases iron absorption

vitamin C

what decreases iron absorption

calcium (competes for same receptor)

what is hemochromatosis

genetic condition causing excessive iron absorption

what is a complication of hemochromatosis

cirrhosis

where is zinc commonly found

meat