Sodium, Potassium, Chloride, Magnesium, Calcium, Phosphorus and Sulfate

Sodium 

  • High absorption rate 95-100% in small intestine 

  • Moves freely in the blood 

  • Only a small loss through perspiration 

  • Blood levels are maintained by the kidneys 

Sodium homeostasis - adrenal glands and hormones 

Hypothalamus 

  1. Stimulates thirst 

  2. Stimulates antidiuretic hormone (ADH) hormone released from the pituitary gland 

  • ADH stimulates water reabsorption in the kidneys = less urine 

Daily needs for sodium 

  • AI: 1,500 mg 

  • UL: 2,300 mg, average american consumes a lot more 

Sodium Excess 

  1. Hypertension - some people are salt sensitive, genetics, ethnicity, age, african americans 

How does high dietary sodium contribute to hypertension? 

  • Water follows solute, over time extra pressure can stiffen vessels 

  • 90% of americans will develop this at some point in their lives

  1. Hypernatremia ( access sodium in the blood) 

  • Occurs when fluids are not replenished after water is lost due to vomiting or diarrhea 

  1. Calcium deficiency - osteoporosis 

Food labels

Low sodium: <140 mg per serving 

Sodium free: up to 5 mg per serving 

Reduced sodium: 25% less then regular version 

Light in sodium: 50% less then regular version 

Potassium (K+)

Major intracellular cation cation 

  • 95% is found within cells 

  • Absorption: about 85% of dietary potassium is absorbed 

  • Excretion: kidneys maintain balance by excreting excess through urine 

Metabolic function of potassium 

  • Fluid and pH balance 

  • Muscle contraction and nerve impulse conduction (maintains regular heartbeat) 

  • Helps lower high blood pressure (DASH diet) 

  • Acts as a major buffer in blood 

-preserves calcium and phosphorus in the bones

-increasing bone density 

Daily needs: 

AI females: 2600 mg, Males: 3400 mg 

DV: 4700 mg 

  • Many americans fall short 

Potassium toxicity 

Hyperkalemia: too much potassium in the blood 

  • Does not occur with food intake 

  • Occurs with supplementation or salt substitutes 

Can lead to→ irregular heartbeat, heart damage, death

Individuals with impaired kidney function and people taking medication that block potassium excretion 

Major sources: 

Veggies and fruits 7 servings 

Dairy 

Nuts, beans 

Potassium deficiency 

hypokalemia : too little blood potassium 

Increased risk of hypertension, kidney stones and loss of bone mass with moderately low intake 

  • Caused by prolonged vomiting or diarrhea

  • Can lead to→ muscle weakness and cramps, glucose intolerance and irregular heartbeat  

What is Chloride (Cl-) ?

An anion attached to sodium as sodium chloride n foods 

  • Salt is 60% chloride and 40% Na

  • Major electrolyte 

  • Found primarily in the blood (88%) 

  • HCL

  • After ingestion, NaCl dissociates in the stomach 

  • Absorbed in the small intestine 

  • Excreted in the urine 

Food sources: 

Table salt 

Processed foods 

Seaweed, tomatoes, olives, lettuce, celery and rye

Magnesium (Mg2+) 

About 60% found in bones, 25% in muscles and remainder in cells 

Bioavailability and absorption: 

Absorption 50% 

A high-fiber and whole grain diet lowers absorption 

Major functions of Magnesium

Needed for metabolism 

  • 300 enzymatic reactions in the body 

  • Needed for synthesis of DNA, RNA and protein 

  • Needed for bone metabolism and cell membrane synthesis 

  • Muscle and nerve function 

  • Blood pressure regulation 

  • Diets abundant in magnesium are associated with lower risk of type 2 diabetes 

Daily needs for magnesium 

UL for supplements signs: diarrhea 

  • Relieves constipation 

  • 350 mg/ day 

  • Americans fall short of consuming adequate magnesium 

Food sources: 

Green leafy veggies 

Whole grains 

Nuts and beans 

Calcium 

  • Most abundant mineral in the body (99% in bones and teeth) 

  • In body cells and fluids needed for: bone structure, muscle contraction, cellular metabolism, wound healing and nerve impulse transmission 

Metabolic functions of calcium 

Calcium builds bones and teeth 

  • Cortical bone: surface of bone 

  • Trabecular bone: inside of bone

Bone Remodeling 

Living tissue 

  • Constantly broken down an reforming during bone remodeling 

  • Reabsorption of old bone, followed by the deposit of new bone 

  • Peak bone mass- maximum bone density attained in life (age 16-30 year) 

Osteoporosis - progressive bone loss

Bones become porous and less dense increasing the risk of fractures 

  • Type 1- results from lower estrogen levels in women experience during menopause; rapid bone loss

  • Type 2- occurs in both men and women; slow loss over time due to aging 

Bone density can be measured by DEXA 

  • Dual energy x-ray absorptiometry measures BMD

  • T-score values are compared with the ideal peak bone density of a healthy 30 year old adult 

  • Healthy normal bone : t- score of -1 to 1 

  • Osteopenia : t-score of -1 to -2.5 

  • Osteoporosis: t-score of less than -2.5 

Metabolic function of calcium

Adequate intake of calcium may: lower high blood pressure , part of the DASH diet 

  • Reduce risk of colon cancer 

  • Reduce the risk of kidney stones 

  • Calcium binds to oxalates in foods 

  • Majority of kidney stones are calcium oxalate stones 

May reduce the risk of obesity 

  • Low calcium intake may stimulate fat production and storage 

Daily  needs for calcium 

  • RDA: 1000 to 1200 mg /day 

  • UL: 2500 mg/ day 

  • Most americans fall short and only consume <800 mg /day

Meeting Calcium needs

  • Bioavailability is increased with vitamin D and lactose 

Proteins effect on calcium 

  • Low protein decreases calcium absorption 

  • High protein increases calcium excretion 

Chronic Deficiency 

  • Osteoporosis, rickets, bone fractures 

Excess

  • Hypercalcemia; constipation, abnormal heartbeat, fatigue, frequent urination, soft tissue calcification, kidney stones and damage 

*when choosing calcium supplement must be taken with vitamin D to ensure absorption

Phosphorus - plays a role in the structure of energy 

2nd most abundant mineral in the body (bones, teeth, muscles, ICF, cell membranes) 

Sources: dairy products, meat, cereal, bran, eggs, nuts, fish

  • Vitamin D enhances absorption 


Deficiencies→ rare; due to chronic diarrhea or poor absorption due to overuse of aluminum- containing antacids; causes bone loss, weakness and loss of appetite

Excess: growing concern; increase intake of processed foods and soda

  • High phosphorus combined with low calcium= decreased bone mass

Why do onions make you cry? 

Onions contain Sulfur and enzymes to break it down → they remain separate until the first chop

  • Combination creates sulfenic acid→ evaporates into a gas

  • When the gas reaches your eyes → triggers an automatic defense mechanism, tears!

What is sulfate (SO4^2-)? 

  • Oxidized form of sulfur 

  • In the body, sulfate is a part of other compounds 

Part of amino acids methionine and cysteine 

  • Give 3-D shape of proteins 

  • Proteins 

  • Thiamin 

  • Biotin 

Functions and sources of Sulfate 

  • Prevent spoilage and discoloration in foods (sulfites) 

  • Sulfites are found in wine 

Individuals who are sensitive may experience: headache, sneezing, swelling of throat and hives

Meat, poultry, fish and eggs – part of amino acids 

  • Legumes 

  • Dairy foods

  • Fruits and vegetables 

  • Beverages: beer, wine and some juices made from municipal water supplies