Question | Answer |
Macrominerals | Calcium, Sodium, Phosphorus, Magnesium, Potassium, Chloride |
Calcium sources | Dairy products, sardines, clams and oysters, cruciferous vegetables, tofu, fortified juices |
Calcium Absorption Reduced by | Oxalate, Phytate, phosphorus (but not likely to affect Ca balance), Menopause, Age, Iron |
Calcium absorption increased by | Vitamin D |
Calcium absorption excretion may be increased by | Protein, Sodium, Chloride |
Calcium absorption supplements | Citrate is best absorbed, take carbonate with food, |
Functions of Calcium | Normal bone (99% of Ca in bones and teeth, Hydroxyapatite- bone crystals, men lose bone mass at high rate in menopause) ;
Intracellular messenger: Activates protein kinase(phosphorylations)
Activates phospholipase |
Functions of Calcium cont'd: | - Muscle contraction : Ca enters muscle and binds to troponin c
- Blood clotting: required for activation of clotting factors
- Normal Blood Pressure
- Colon Cancer Prevention |
Calcium Deficiency | - Decrease in serum : Tetany = uncontrolled muscle contraction
- Decrease in bone : Rickets in children; Osteoporosis in adults
- Decrease intake : HTN, Colon Ca, Weight Gain |
Calcium Assessment | Serum Calcium , Serum ionized Ca (direct measure of active calcium levels), Bone mass/density Ca (best measured by Dexa) |
Phosphorus sources | Dairy, MFP, Nuts/Seeds, Legumes, Soft Drinks |
Phosphorus Absorption | - Decreased by: Phytates, Magnesium Calcium
- Increased by : Vitamin D |
Phosphorus Fuctions | - Bone mineralization = hydroxyapatite
- Energy-rich compounds = ATP, creatine phosphate
- Phospholipids = cell membranes
- Coenzyme form of vitamins = PLP, NADPH, TDP, TPP
- Nucleic acid structures = Alternates with pentoses to form back bone |
Phosphorus Deficiency | - Rare due to widespread sources |
Phosphorus at risk | Antacids or phos-binders
Starvation - refeeding sydrome |
Phosphorus deficiency symptoms | Children : rickets
Adults : osteomalacia
Muscular weakness
Loss of appetite
Hemolytic anemia |
Phosphorus toxicity | AT RISK: renal failure
Symptoms : renal bone disease, soft tissue calcification |
Phosphorus assessment | Serum phosphorus |
Magnesium Sources | Nuts, Legumes, Whole grains, Green Vegetables |
Magnesium absorption decreased by | phytates, phosphorus
increased by: vitamin D |
Magnesium functions | Enzyme cofactor = kinases
- Protein and nucleic acid synthesis
- Bone structure
- Blood pressure = vasodilator, and cofactor for fatty acid metabolism and synthesis of prostaglandins |
Magnesium deficiency | Muscle effects = tremors, weakness, spasms
N/V, anorexia
Osteporosis?
Low intakes related to heart disease |
Magnesium toxicity | At risk: renal failure
Symptoms: diarrhea |
Magnesium Assessment | Serum concentration and urine excretion |
Sodium sources | Processed foods, pickeled foods, table salt, softened water, MSG |
Sodium functions | - Primary extracellular cation
- Regulation of fluid status and blood pressure
- Nerve transmission (depolarization)
- Acid base balance ( Sodium exchanges for H+ at kidney)
- Absorption of glucose |
Sodium deficiency | Rare, but may cause intracellular edema
- Caused by fluid loss and replacement of water only |
Sodium toxicity | - increase blood pressure
- stiff arteries
- AT RISK: renal failure, heart failure |
Potassium sources | Unprocessed foods, Fruits/Veggies, Peanut butter, Dairy, Legumes, salt substitutes |
Potassium Functions | - Primary intracellular cation
- Nerve transmission
- Regulation of fluid balance and blood presure |
Potassium deficiency | AT RISK : fluid lost, K-wasting diuretics, Starvation ( refeeding syndrome)
- Hypertension
- Hypokalemia = muscle weakness, mental confusion, arrythmias |
K toxicity | Usually not due to diet
AT RISK: renal failure |
Chloride sources | Same as sodium, Eggs Seafood |
Chloride functions | - Fluid/electroylte balance (opposes sodium)
- Component HCL
- Acid/Base balance = lose H+ during vomiting, exchange for bicarbonate in RBCs |
Chloride deficiency | AT RISK: excess fluid loss
SYMPTOMS: convulsions |
Chloride toxicity | AT RISK: dehydration
INCREASE BP: as salt |
Chloride Assessment | Serum concentration |