MINERALSclassification

Major minerals• needed in the body in the largest amounts

requirements >100 mg/day

calcium, sodium, potassium, phosphorus

• There are many more minerals and trace elements, however, we will be focusing on the ones that are the most problematic in human nutrition and those which are important for chronic disease prevention.

CalciumMain functions:

– bone/tooth formation– regulation of nerve transmission, blood clotting,

contraction of muscles– helps maintain normal blood pressure

Stored in:– 99% of the total calcium in the body is stored in the

bones– 1% of the total calcium in the body is found in the

blood

• Calcium stored in the bones serves as a reservoir of calcium. Its there to help maintain blood calcium levels when intake of calcium is low.

• A chronically poor intake of calcium, over a number of years, causes a lot of calcium to removed from the bones to supply the blood (which is used for more immediate needs like muscle contraction, nerve transmission, etc).

• Eventually, calcium loss from the bones results in reduced bone density and this condition is known as osteoporosis. We will discuss osteoporosis in a bit.

• Calcium has a low bioavailability so anything that you can do to enhance, and therefore, improve calcium absorption is important.

• These are factors which enhance calcium’s bioavailability:– Vitamin D:

• fortunately one of the best sources of calcium (milk) also contains Vitamin D. Women taking calcium supplements should also consider taking a calcium supplement that has some Vitamin D to help with absorption.

– Lactose: • again, milk, our best calcium source also contains lactose. (What is

lactose?)– Gastric acid:

• is the acid secreted in your stomach for digestion; calcium absorption is enhanced in an acidic environment—since acid is secreted whenever you eat food, its best to take a calcium supplement with food.

– Need: • any time you body needs more calcium, during pregnancy and periods of

active growth such as infancy and adolescence, for example, our bodies can absorb more calcium

Factors which decrease Calcium absorption

– Too much fiber in the diet• >35 gms/day• for most Americans, this is not a problem, since the average fiber

intake is ~10-15 gms/day

– Age• As we age, we produce less gastric acid

– Excess use of laxatives– Too much phosphorus in the diet

• Our main source of phosphorus is soda—and we drink a lot of soda, especially children and teens—which could be putting thier bones at risk, especially when they substitute soda for milk

– Vitamin D deficiency– Too much coffee, tea

Osteoporosis– a chronic, degenerative disease– characterized by:

• bone loss• decrease in bone density

– 2001: • 1.5 million fractures annually• costs $17 billion/yr ($47 million per day)

– prevention is key

. Bone loss from osteoporosis

Normal bone

Bone loss occurs primarily in thehips, spine and wrist

A DEXA scan is used to measurebone density

• Osteoporosis is a major public health threat for an estimated 44 million Americans

• In the U.S. today, 10 million individuals are estimated to already have the disease and almost 34 million more are estimated to have low bone mass, placing them at increased risk for osteoporosis. 

• Of the 10 million Americans estimated to have osteoporosis, eight million are women and 2 million are men.

• 34 million Americans, or 55% of the people 50 years of age and older, have low bone mass, which puts them at increased risk of developing osteoporosis and related fractures. 

• Significant risk has been reported in people of all ethnic backgrounds.

• While osteoporosis is often thought of as an older person's disease, it can strike at any age

• 80% of those affected by osteoporosis are women.

• 20% of those affected by osteoporosis are men.

• One in two women and one in four men over age 50 will have an osteoporosis-related fracture in their lifetime.

• Osteoporosis is responsible for more than 1.5 million fractures annually, including: – 300,000 hip fractures; and approximately  – 700,000 vertebral fractures, – 250,000 wrist fractures; and – 300,000 fractures at other sites.

Osteoporosis Risk Factors

• Increased age• Being female• Small boned, thin women• People with a history of

anorexia nervosa• Caucasian/Asian women

• Family history• Sedentary lifestyle• Smoking, heavy drinking• Long term use of certain

medications such as prednisone

• Remember what a risk factor is?? – It is something that increases the chances of

developing a medical condition

• The more risk factors one has, the higher the chance of developing the medical condition. Having one or even 2 risk factors does not necessarily mean one will definitely develop a problem, just that the chances are higher.

Preventing Osteoporosis

• Consume adequate calcium and vitamin D in your diet-- throughout life

• Get regular physical activity, especially weight bearing exercise

• Be moderation in alcohol/caffeine consumption

• Prevention is key because currently, there is no cure

Treatment

• Hormone replacement therapy (estrogen)• Calcium, vitamin D supplements• Drugs

– Bisphosphonates– Alendronate (brand name Fosamax®) – Risedronate (brand name Actonel®) – Calcitonin (brand name Miacalcin®)– Raloxifene

• Bisphosphonates are a family of drugs used to prevent and treat osteoporosis. – alendronate (Fosamax ®)– etidronate (Didrocal ®) – risedronate (Actonel ®).

• How do they work? – Bisphosphonates bind permanently to the surfaces of

the bones and slow down the osteoclasts (bone-eroding cells). This allows the osteoblasts (bone-building cells) to work more effectively.

• How effective are they?– Bisphosphonates increase bone density and prevent

fractures of the spine (vertebral fractures).

Calcium Needs

Women

age 19-50 1000 mg

> age 51 1200 mg

pregnancy 1000 mg

Men

age 19-50 1000 mg

Current average intake: 500-600 mg per day---only about half of what needs are

Food sources

milk, cheese, yogurt

foods made with milk/cheese (pudding, pizza)

Calcium fortified orange juice

Calcium fortified soy milk

Calcium supplements

– Who should take them? • people with lactose intolerance, • people who dislike milk• any one with a milk allergy (not the same thing as being

lactose intolerant)

– Side effects of calcium supplements• constipation, gas • decreases iron absorption

– if you take an iron supplement for iron deficiency anemia, or to prevent anemia, take your calcium supplement and iron supplement at different times of the day

Tips for improving bioavailability from calcium supplements

calcium citrate is highly bioavailable (eg: Citracal)

take chewables (Tums with Calcium, Viactiv)

split your doses (take only 500 mg at a time)

take with food

don’t take more than 1500 mg/day

avoid oyster shell calcium, dolomite, bone meal, coral calcium

Phosphorus

Main functions:– assists many enzymes/vitamins to extract energy from

ATP—adenosine triphosphate

– component of cell membranes

– bone structure

Requirements– same as calcium– excess phosphorus, esp. combined with poor calcium intake,

may contribute to bone loss • Teens, or anyone, who drink a lot of soda and little or no milk are

increasing the risk of bone loss…a real problem in the US

Deficiency– None— we have problems with excessive intake in U.S.

Food sources– Soft drinks, milk, cheese, baked goods, meat, food additives

Sodium (Na+)

Sodium chloride (NaCl) known as “table salt”

Main functions:– fluid/water balance– conduction of nerve impulses– glucose transport/absorption– acid-base balance

Physiological requirements: 500 mg/day– This is the amount we need every day to prevent a

deficiency

Average U.S intake: 5000-8000 mg/day

Recommended intake for good health <2400 mg/day

How does this compare with the average intake in the US?

A grain of salt

Food sources

Table salt: 1 tsp = 2250 mg

Naturally occurring Na Food serving size Na+ (mg) milk 1 cup 120 meat (raw) 3 oz 50 fruits ---- <10 vegetables ½ cup 5-50

Sodium is naturally present in almost all foods—so it is impossible to have a sodium free diet

Sodium Added During Processing

Food serving size Na (mg) ham 3 oz 1200 bologna 2 slices 580 canned soup 1 can 800-1000 cottage cheese 1 cup 920 McDonalds shake medium 300 dill pickle 1 whole 850 soy sauce 1 tbsp 1029

• We get most of our sodium from salt added during processing…not from the salt we add at the table to foods.

• Remember what your physiological requirements are….if you eat one can of soup (not the low sodium kind) you are already consuming twice your needs and 1/3 of what is recommended for an entire day.

Sodium content of select foodsTaco bell bean burrito (1) 1100 mgMcD. Quarter Pounder w/cheese 1300mgPizza Hut Stuffed Crust

Pizza (2 slices) 2850 mgChicken wings (12) 1750 mgKraft Mac and cheese

(1 cup, prepared) 750 mgTaco Bell Taco (1) 330 mgAmerican cheese (1 slice) 300 mgBK Whopper 900 mg

Sodium: major food sources

canned, cured, smoked meats– bologna, salami, pepperoni, sausage, ham

canned soupscanned vegetablesBouillon, Ramen noodlesolives, sauerkraut, anchovieschips, crackersseasonings (garlic salt, celery salt), MSG

(monosodium glutamate)some frozen dinners

Hypertension (high blood pressure)

Blood pressure– the measurement of how hard your heart has to

work to pump blood from your heart to the rest of your body

– Optimal blood pressure: systolic <120

diastolic <80

Hypertension

Causes of hypertension:1. No known cause

this type of hypertension occurs in 90-95% of people diagnosed with hypertension

2. Kidney disease kidney disease is the cause of hypertension in only

5-10% of people with hypertension

• The cause of high blood pressure is unknown in the majority of cases….there are many risk factors, but the exact cause is not known. For a small percentage of the US population, kidney disease causes their high blood pressure.

Symptoms– None until significant organ damage has occurred

• Headaches, visual problems• Hypertension is called the “silent killer” because there are

no symptoms and therefore, most people do not know they have hypertension

Long term complications of uncontrolled hypertension– stroke– kidney disease– blindness/impaired vision– heart failure

• Hypertension is known as “the silent killer” because you can have high blood pressure for years and years and yet never know it because there are no outward signs or symptoms.

• That is why regular monitoring is important, especially if you are at high risk. You can have your blood pressure checked free of charge at most supermarkets and pharmacies.

HypertensionRisk Factors

– older age• as we age, our blood

pressure increases

– family history

– obesity

– diabetes/insulin resistance• Type 1 or 2

– smoking, heavy alcohol intake

– African-American descent• usually develop high BP at an

earlier age and it can be more severe

– heart disease

Hypertension: Prevention

low to moderate sodium consumption

lose weight if overweight

eat a diet high in fruits, vegetables

consume low fat dairy products, whole grains

emphasize poultry, fish, nuts; eat less red meat

get some exercise

The DASH diet

• The DASH diet is a plan that has been clinically proven to help reduce blood pressure

• Information regarding the DASH diet is available at the following website.– http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/ – (Or download the pdf file about the dash diet linked on

the syllabus)

• Read the article available at the CSPI website:– http://www.cspinet.org/nah/dash.htm

Potassium

Main functions:– conduction of nerve impulses– critical in maintaining the heartbeat– fluid and electrolyte balance

Deficiency:– 90% we eat is absorbed

• potassium has a high bioavailability– Low blood levels may be caused by:

• excessive vomiting, prolonged diarrhea, certain diuretics, laxative abuse

Potassium

Toxicity– can occur with potassium supplements (KCl)

Food sources

leafy greens (spinach)

oranges, orange juice, broccoli, bananas, tomatoes