Chapter 11: Water and the Major Minerals

1
Recap of last lecture

• Minerals major
• Hypertension
• Bone health

2
20 Outline for today

• Trace Minerals
• Hypertension
• Bone health
• Next time Alcohol

3
News item

• Consumer Reports Finds Nearly Half of Chickens
  Tested ContaminatedAnalysis Of Bacteria Shows
  Significant Resistance To Important Human
  Antibiotics
• Affected consumers may be sick longer, possibly
  with more serious illness
• YONKERS, NY-In a nationally representative
  analysis of antibiotic resistance in store-bought
  chicken, Consumer Reports (CR) tested 484, fresh,
  whole broilers and found salmonella or
  campylobacter-the bacteria most likely to give
  Americans food poisoning-in about half the
  samples. The study is the largest of its kind
  known to Consumer Reports. The results are
  published in the January 2003 issue of Consumer
  Reports and the entire article is available free
  at http//www.consumerreports.org/. Ninety
  percent of the campylobacter bacteria tested from
  the chicken and 34 percent of the salmonella
  showed some resistance to one or more antibiotics
  often used to treat people. The presence of
  resistant strains in chickens has been linked to
  feeding them drugs to prevent or reduce sickness
  and to speed growth."As a result, the estimated
  1.1 million or more Americans sickened each year
  by undercooked, tainted chicken, or by food that
  raw chicken juices have touched, may stay sick
  longer, possibly with more serious illnesses.

4
The Trace Minerals

• Needed in very small amounts
• Are essential
• Difficult to study due to the trace amounts
  needed by the body
• Food content dependent on soil content
• Animal sources of mineral are generally better
  absorbed.

5
Table 12.2a
6
Table 12.2b
7
Table 12.3
8
Iron

• Found in minute amounts in every cell
• Typically about 15 is absorbed
• Heme iron Vs. Nonheme iron
• Heme found in animal products are better absorbed
  than nonheme
• Vitamin C enhances absorption

9
Regulation

• Like many minerals, the body balances its iron
  levels through a combination of
• Absorption (major control) (men 6 women 13)
• Transport (transferrin)
• Storage (ferritin)
• Excretion
• Reason for close control is that iron is
  potentially toxic

10
Absorption of Iron

• Determined by bodys need
• Acidic environment
• Upper small intestine is absorption site
• Hindered by phytic acid, oxalic acid, high fiber,
  high calcium and phosphorous (milk), polyphenols
• Non-heme iron facilitated by acids (Vitamin C)
  and meats, fish, poultry

11
Mucosal Block
12
Functions of Iron

• Hemoglobin in red blood cells
• Transports oxygen and carbon dioxide
• High turnover, high demand for iron
• Myoglobin in muscle cells
• Electron transport chain
• Enzyme cofactor
• Immune function
• Drug-detoxification pathway

13
Iron-Deficient Anemia

• Most common form of anemia
• Low levels of hemoglobin and hematocrit
• Insufficient intake and store
• Reduction in the production of red blood cells
  and oxygen capacity
• Infant, toddler, chronic blood loss, vegan,
  runners, and women of childbearing years are most
  at risk
• Paleness, brittle nails, fatigue, difficulty
  breathing, poor growth

14
Food Sources of Iron

• Red meats
• Enriched grains
• Fortified cereals
• Milk is a poor source
• Cast iron pots

15
Iron Needs

• RDA is 8 mg/day for adult male
• RDA is 18 mg/day for female age 11 to 50
• Assumes that 18 of dietary iron is absorbed
• Average intake exceeds RDA for men, low for women

16
Iron supplements

• Iron often a concern for women of childbearing
  age, who may not get enough of it from food to
  make up for losses of iron-rich blood during
  menstruation. Women who take iron supplements (or
  multivitamin/mineral pills that contain iron),
  should take them at mealtime, or with a glass of
  juice.
• Certain foods, including iron-rich meat, fish,
  and poultryand vitamin C-rich juice, fruits, and
  vegetableshelp the body to extract more iron
  from supplements.

17
Iron supplements contd

• If youre a tea or coffee drinker, however, its
  best to avoid those two beverages when taking an
  iron supplement or eating an iron-rich meal.
• Substances in coffee called polyphenols can
  inhibit absorption of iron from plant foods by as
  much as 40 percent.
• Tannins, the polyphenols found in tea, can
  inhibit iron absorption up to 70 percent. Wait
  about an hour and a half before taking your
  beverage break.

18
Toxicity of Iron

• Can be serious, especially for children
• Diarrhea, constipation, nausea, abdominal pain
• Upper Level is 45 mg/day
• Causes death due to respiratory collapse (shock)
• Hemochromatosis
• Genetic disease (carriers can also over-absorb)
• Iron deposits which can lead to organ damage
• May go undetected until 50-60 yrs of age when
  organ fails
• Most common cause of poisoning of kids lt6

19
Zinc

• Essential nutrient
• Better absorption from animal sources
• Competes with iron for absorption
• Deficiencies cause growth retardation and poor
  sexual development

20
Absorption of Zinc

• Influenced by the foods consumed
• 40 of zinc from an animal source is absorbed if
  bodys needs are great usually lt15
• Dependent on bodys need
• Presence of phytic acid decrease absorption
• Calcium supplement decrease zinc absorption
• Competes with copper and iron absorption
• Inhibited by high non-heme iron intake (supps)

21
Functions of Zinc

• Cofactor to many enzymes
• Synthesis of DNA
• Protein metabolism, cell membrane
• Wound healing, immune function, growth
• Development of sexual organs and bones
• Insulin function
• Zinc finger proteins gene regulation
• Component of superoxide dismutase

22
Food Sources of Zinc

• Animal products
• Shell fish
• Legumes
• Not part of the enrichment process
• RDA for women is 8 mg/day
• RDA for men is 11 mg/day
• Daily value is 15 mg
• Average intake is marginal for women and adequate
  for men

23
Toxicity of Zinc

• Upper Level is 40 mg/day
• Inhibits copper absorption
• Reduces HDL
• Increases risk of heart disease
• Diarrhea, cramps, Nausea, vomiting
• Depressed immune function
• Do not exceed 100 mg/day without medical
  supervision

24
Deficiency of Zinc

• Common in diets high in cereals
• Diarrhea and chronic infection lead to excessive
  excretion
• Chronic iron supplementation
• Burns, surgery, chronic diarrhea
• Also in certain diseases
• Malabsorption
• Diabetes, kidney disease

25
Zinc and the common cold

• 11 good studies 5050 /-
• Lozenges readily available may shorten time
  period if started within 24 h
• Side effects very common bad taste, sore mouth
• Long term use -gt copper deficiency
• Probably not good idea for children

26
Contd

• Recent research suggests that the effect of zinc
  may be influenced by the ability of the specific
  supplement formula to deliver zinc ions to the
  oral mucosa.
• Additional research is needed to determine
  whether zinc compounds have any effect on the
  common cold.

27
Selenium

• Readily absorbed
• Excreted through the urine and feces
• Co-factor for glutathione peroxidase
• Protects the heart and other cells from oxidative
  damage
• Works together with vitamin E
• Cancer prevention
• Only 25 yrs since found to be essential

28
Deficiency of Selenium

• Muscle pain
• Muscle wasting
• Cardiomyopathy

29
Food Sources of Selenium

• Fish, meat (organ meat), egg, milk, shell fish
• Grains, seeds, nuts dependent on soil content
• RDA for adults is 55 ug/day
• Average intake exceeds RDA

30
Toxicity of Selenium

• Upper Level is 400 ug/day
• Garlicky breath
• Hair loss
• Nausea, vomiting
• Weakness
• Rashes
• Cirrhosis of the liver

31
Iodine

• Found in an ion form, iodide
• Used for thyroid hormone synthesis
• Regulates metabolic rate, growth, development
• Thyroid gland enlarges (goiter) with low intake
  of iodide
• Cretinism is the stunting of fetal growth and
  mental development as a result of low iodide diet

32
Food Sources of Iodide

• Iodize salt (1/2 tsp. meets RDA for iodide)
• Saltwater fish, seafood, dairy, grains
• Sea salt is a poor source (loss during
  processing)
• Plant source dependent on soil content
• RDA for adult is 150 ug/day (50ug to prevent
  goiter)
• Average intake exceeds RDA

33
Toxicity of Iodide

• Thyroid hormone synthesis is inhibited
• Toxic goiter results
• Consumption of seaweed
• Upper Level is 1.1 mg/day

34
Fluoride

• Role in prevention of cavities
• Resists acid and dental caries
• Fluoride inhibits bacterial growth that may cause
  cavities
• Fluoridated water (1ppm)

35
Food Sources of Fluoride

• Fluoridate water (0.2 mg/cup)
• Tea
• Seafood, seaweed
• Toothpaste
• Adequate intake is 3.1 -3.8 mg/day for adults
• Typical fluoridate water contains 0.2 mg/cup

36
Toxicity of Fluoride

• Mottling of the teeth in children
• Limit toothpaste to pea size for children
• In high amounts can weaken teeth in children
• Upper Level is 10 mg/day

37
Chromium

• Not much understood
• Role in Type II diabetes
• May increase the transport of glucose across the
  cell membrane
• Impaired glucose tolerance with low intake
• Elevated cholesterol and triglyceride with low
  intake

38
Food Sources of Chromium

• Little information
• Egg yolk
• Bran, whole grain, cereal
• Organ meat, meat
• Beer
• Plant source dependent on soil content
• Adequate Intake is 25 - 35 ug/day for adults
• Average intake meets the AI

39
Toxicity of Chromium

• No toxicity from foods
• No Upper Level
• Exposed to chromium waste sites
• Lung liver damage

40
Other Minerals

• Copper
• Maganese
• Molybdenum
• Boron
• Nickel
• Silicon
• Vanadium
• Arsenic