Macrominerals

Question 1

Ca Function

Adequacy

DRI

Answer 1

bone mineral matrix - 99% of Ca resides in bone hydroxyapatite

based on Ca balance studies and intake level to achieve ↑ bone mineral content in women

RDA for adults 19-50
UL = 2500 mg
- Risks associated with long term supplementation or excessive supplementation Ca levels associated with CVD (Ca deposits)

Question 2

P function

Adequacy

DRI

Answer 2

buffers acid/alkali to maintain normal pH
storage and transfer of energy from metabolic fuels (phosphorylation and activation)

EAR based on serum phosphate levels (lower end)
Plateauing bone mineral testing

RDA all adults
UL = 4000 mg
- Above UL can affect Ca regulation and deposition of Ca in soft tissues

Question 3

Mg function

Adequacy

DRI

Answer 3

bone mineral - 50-60% in bone
- ⅓ used as reservoir to maintain [Mg] extracellularly
Cofactor for more than 300 enzymes

maintenance of total body Mg (balance studies)

RDA age and sex differences under 30/over 30
- decreased Mg retention after 30
UL = 350mg only supplements
- For diarrhea, bloating symptoms of supplementation

Question 4

Fe Function

Adequacy

DRI

Answer 4

protein component and cofactor for enzymes in oxidative metabolism

basal losses (sweat, urine, feces, skin cells), menstrual losses, fetal requirements, growth
- question of bioavailability between heme (well absorbed) and nonheme (absorption dependent on dietary factors)

based on maintenance of [Fe] stores with minimal serum [ferritin] of 15 mcg/L

RDA differs by sex due to menstrual losses (19-50)
RDA differs by source type (veg or meat)
Additional supplementation in pregnancy 16-20 mg

UL = 45 mg
- based on constipation and gastro disturbances

Question 5

Sulfur Function

Adequacy

DRI

Answer 5

Component of sulfur AA: cys, met, cystine
Glutathione component

None

None

Question 6

Potassium function

Adequacy

DRI

Answer 6

Lowering blood pressure (intracellular electrolyte to balance Na)
Reduced risk of kidney stones
Reducing bone loss

no biomarker available (balance studies not effective)

AI –> Insufficient evidence for EAR
AI based on median intake of apparently healthy groups of people
No UL

Question 7

Na DRI

CDRR

Answer 7

AI for sedentary and active adults
1.5g/d or more

UL for sedentary adults is 2300 mg (CDRR)
- associated with processed foods

Question 8

Macrominerals w/ No UL

Answer 8

No UL: S and K

Question 9

Macrominerals w/ AI

Answer 9

AI: S (no rec), K, Na

Question 10

Macrominerals which differ by sex

Answer 10

Sex differences: Mg and Fe