Chapter 3

1. Chapter 3 The Micronutrients of Balanced Meals: Vitamins, Minerals, and Phytochemicals

2. Introduction Vitamins, minerals, and phytochemicals, as found in foods, are necessary to help the body function in a variety of ways. Supplements have been available since the early 20th century, but much remains to be known about when supplements are helpful and harmful. A well-balanced diet can provide all needed nutrients, although supplements, used wisely, can serve a vital role.

3. Plants Produce Vitamins Through Their Genetic Makeup Vitamins are organic and can be broken down Vitamins are grouped based on their ability to dissolve in fat or water Fat-soluble vitamins—A, D, E, K (stored in the body; require dietary fat intake for absorption) Water-soluble vitamins—Bs, C (not stored in the body; needed on a daily basis)

4. Medical Causes of Vitamin Deficiency Fat-soluble vitamins (A, D, E, K) Fat-malabsorption due to: Cystic fibrosis Surgical removal of the ileum (lowest portion of the small intestine) Medications/fat substitutes (Olestra) that inhibit absorption of fat Water-soluble vitamins (B vitamins, vitamin C) Medications such as proton pump inhibitors and anti-epileptic medications Excess urination due to diuretic treatment or excess fluid intake

5. Vitamin A and Beta Carotene Two types of vitamin A: Precursor—carotene (deep orange color as found in carrots, sweet potatoes, cantaloupe; also found in dark green, leafy vegetables); the liver uses the precursor form to make vitamin A Oranges are the exception to the color rule Because the precursor form allows production of vitamin A, it is simply referred to as vitamin A Preformed—retinol/retinol palmitate (liver, supplements); also found in water-soluble forms (the most toxic and form typically used in food fortification) Carotene—harmless but can turn skin to orange color; avoidance of carotene allows return to normal color

6. Functions of Vitamin A Vitamin A is needed for: Retinal health and night vision Promoting good immunity Maintaining skin health (epithelial tissue) Promoting bone growth Reproduction Preventing a form of iron deficiency (Kelleher and Lonnerdal, 2005)

7. Vitamin D:“Sunshine Vitamin” Dietary intake is either from fortified foods (milk) or as naturally found in fish liver (cod liver oil or whole fish [with liver]) Cod liver oil advised by doctors to prevent rickets in children in the early 20th century Sun allows conversion in the skin of cholesterol into vitamin D Melanin interferes with sun’s ability to produce vitamin D Compromise message of sun exposure to prevent skin cancer while meeting vitamin D needs 20 minutes of sun exposure without sunscreen lotion Latitudes north of Philadelphia: the sun is too weak to make vitamin D in the skin from September through March Increased intakes of at least 800 IU advised in Northern climates; may be as many as 2000 IU needed

8. Functions of Vitamin D Allows calcium absorption for strong bones and teeth and allows the body’s use of calcium Needed for a strong and healthy immune system Helps prevent autoimmune diseases (type 1 diabetes, multiple sclerosis [MS]—Olympic skiers have the highest rate of MS) May help prevent “winter blues,” or seasonal affective disorder (SAD) Helps regulate blood pressure and acts as a tumor suppressant to help prevent cancer

9. Vitamin D Deficiency Can cause bone loss, rickets, and secondary hyperparathyroidism Breastfed infants are advised to take vitamin D supplements to help prevent rickets Screening of vitamin D status advised for high-risk groups, including those treated for epilepsy (Nettekoven et al., 2008) Other associations with deficiency: Impaired neuromuscular function with muscle pain Tuberculosis and/or impaired immunity Rheumatoid arthritis Multiple sclerosis (MS) Inflammatory bowel disease Hypertension Diabetes

10. Vitamin E: Tocopherol Originally discovered as necessary for rat reproduction Appears necessary for fetal growth An antioxidant vitamin—helps prevent cellular damage caused by oxidation Helps regulate cell signaling and gene expression Sources—nuts and peanut butter, vegetable oils, wheat germ

11. FYI Vitamin E during pregnancy may reduce risk of childhood asthma (Seaton, 2008) Vitamin E inadequacy during pregnancy may be linked with low birth-weight and smaller head circumference (Masters et al., 2007) Excess or deficiency of vitamin E appears linked to inflammation (Wagner et al., 2008; Gianello et al., 2007)

12. Vitamin K: Phylloquinone Allows for clotting of blood Involved in vascular function and bone metabolism Evidence it supports bone growth Found in green leafy vegetables, green tea, cauliflower, butter, soybean oil, legumes Intestinal bacteria produce vitamin K Only concern is usually related to Coumadin (an anticlotting medication), which necessitates stable intake of vitamin K; antibiotics used to treat gram-negative bacteria can cause vitamin K deficiency, with potential for increased effect of Coumadin

13. Deficiency Concerns of Vitamin K Newborn infants generally require injection at birth because of lack of intestinal bacteria Intracranial hemorrhage (ICH) at 1 to 2 months of age; signs and symptoms: vomiting, absence of pupil reaction, fontanel bulging, convulsions, irritability with coma Vitamin K supplement needed for infants with antibiotic treatment, diarrhea, liver problems, or breastfeeding With long-term use of antibiotics for gram-negative bacteria for children and adults, supplementation is advised

14. Water-Soluble Vitamins Water-soluble vitamins B vitamins B1: thiamin B8: biotin* B2: riboflavin B9: folate* B3: niacin B12: cobalamin B5: pantothenic acid* choline B6: pyridoxine and related substances *not generally referred to numerically Vitamin C (ascorbic acid)

15. B Vitamins Easily destroyed with cooking Serve as cofactors to allow cellular metabolism; needed for energy production in the mitochondria Most B vitamins found in whole grains and legumes B2 found mainly in milk, eggs, peanuts, organ meats B3 requirement met, in part, by production from the amino acid tryptophan B12 found in animal products only

16. Hyperhomocysteinemia A condition related to deficiency of B vitamins Linked with neurodegenerative diseases and dementia (Hermann et al., 2007) An increased intake of the B vitamins (especially folate, B6, and B12) may improve brain function Other conditions that may benefit with increased intake of B vitamins include Parkinson’s disease with L-dopa medication Multiple sclerosis Epilepsy and Acid-Reflux due to medications

17. Folate: Names for “Foliage” May be referred to as vitamin B9 Named for a chief source of folate: foliage or dark-green, leafy vegetables Active form: folic acid, formed with vitamin C Aids in metabolism of DNA, promotes chromosomal health, red blood cell formation Helps prevent spina bifida if consumed in first few days after conception Women of childbearing years advised to consume 400 mcg folate daily Processed white-grain products are fortified with folate to lower the risk of infants born with spina bifida (a form of neural tube defect)

18. Vitamin B12: Cobalamin Important in DNA synthesis and may affect bone formation (Tucker et al., 2005) Found in animal-based foods only; contains the mineral cobalt (hence the name cobalamin) Deficiency causes irreversible nerve damage, megaloblastic anemia Vitamin B12 supplementation may not be adequate; intramuscular B12 injections commonly provided for the elder population or persons with malabsorption (e.g., after gastric bypass surgery)

19. Vitamin C (Ascorbic Acid): Water-Soluble Derivative of Glucose First vitamin identified from experience of “limeys” (British sailors)—scurvy avoided by eating lemons (then called limes) Scurvy = severe deficiency; mild deficiency related to bleeding gums and/or loose teeth, easy bruising, pedal edema, arthralgias (joint pain), and joint swelling Acts as “glue” to hold body cells together Promotes immunity and wound healing Promotes bone growth, collagen, and growth of all body tissues Serves as an antioxidant to reduce levels of free radicals (reactive oxygen species) for reduced risk of cellular damage Found in fruits and vegetables only (e.g., leafy greens, citrus, melons, potato, green peppers, berries, tomatoes)

20. General Functions of Minerals Serve as building materials and found in all body constituents Bone and teeth (calcium, phosphorus) Hair, nails, and skin (sulfur) Blood (iron in hemoglobin) Serve as regulators of body metabolism Muscle contraction and relaxation (calcium, potassium) Blood clotting (calcium) Coenzymes (zinc, magnesium, potassium)

21. Calcium Chief mineral in bones and teeth Allows for muscle contraction and function of nervous system and blood coagulation Found in high amounts in milk, soybeans, bones (i.e., bones of salmon/anchovies), some leafy greens: collards, seaweed, hard water Chief age for bone mineralization <35 years Osteoporosis risk factors—low calcium and/or vitamin D intake, Caucasian or Asian heritage, low body weight, rheumatoid arthritis, steroids, smokers, alcohol abusers and alcoholics

22. Magnesium: Part of the Chlorophyll Molecule Involved in strong bone formation Critical to 300 metabolic enzymes Regulates heartbeat, helps transport potassium and calcium, helps with muscle contractions, lowers inflammation Involved in energy metabolism Can serve as a calcium channel blocker (used to control hypertension and migraines) Bound with chlorophyll (green leafy vegetables) and also found in milk, legumes, fish, eggs Can be lost with diuretics and excess urination (as found with uncontrolled diabetes)

23. Phosphorus Helps enzymes act in energy metabolism Only second to calcium in body content Primarily found in bones A ratio of 1.5 calcium to 1.0 phosphorus intake advised in early infancy to prevent tetany Widely found in foods; added to carbonated beverages

24. Potassium Promotes regular heartbeat; altered levels contribute to irregular heart beat A key “electrolyte” (related to electric flow) Critical for intracellular enzyme functioning Found in all foods; easy to obtain; very high amounts in green leafy vegetables, whole grains, milk, citrus fruits, bananas, potatoes, tomatoes Excess avoided with kidney disease or use of ACE inhibitor Rx (avoid potassium chloride [KCl] in salt substitutes)

25. High Potassium Foods >500 mg 1 banana 1 cup tomato or orange juice 12 oz milk 1½ cups leafy green vegetables 1½ cups melon 1 cup beets 1 medium potato

26. Sodium Serves as an essential electrolyte Found in salt as sodium chloride (Na+Cl-), minor amounts found in leafy green vegetables, milk, eggs, meat; very low amounts in fruits and unprocessed grains 1 teaspoon salt contains 2400 mg Na+ The Upper Limit (UL) of safety set at 2300 mg The DASH diet (Dietary Approaches to Stop Hypertension) advocates restriction of 1500 mg “No added salt” diet defined as less than 4000 mg Na+

27. Chloride Found in extracellular fluids and serves as an electrolyte Found in gastric juice as part of hydrochloric acid Deficiency found in conjunction with sodium depletion Excess levels due to dehydration

28. Fluorine Found in fluoride tablets and fluoridated water as used to promote strong teeth formation in children Also found in fish, tea, and gelatin Can be toxic and lead to mottling of teeth

29. Iodine Found in thyroid hormones and involved in general metabolism Has an antioxidant function Sea fish and seaweed naturally high in iodine; iodized salt is an important alternative source Deficiency states: hypothyroidism, goiter (see slide)—linked with reduced IQ, and cretinism, a form of mental retardation, of infants born to women with iodine deficiency (now rare because of iodized salt use) Excess intake leads to hyperthyroidism

30. Goiter: Caused By Iodine Deficiency Goiter. (From Swartz MH: Textbook of physical diagnosis: history and examination, ed 5, Philadelphia, 2006, Saunders.)

31. Iron Carries oxygen in red blood cells Prevents iron-deficiency anemia Heme—animal sources: especially liver, red meat; heme form readily absorbed Nonheme—plant; need vitamin C source to convert to heme form for enhanced absorption Iron frying pans are a source of iron, with long duration of cooking and acidic foods leading to highest iron absorption

32. Iron Supplementation or Fortified Foods Advised for those with iron-deficiency anemia as determined with iron studies: Percent iron saturation TIBC (total iron-binding capacity) Transferrin levels (a protein that transports iron) Ferritin (storage form of iron) With high-risk populations: pregnancy, growing children, women with menstrual cycle—related imbalances, malabsorptive conditions Excess can cause hemochromatosis and lead to diabetes, liver, and heart damage; dx: transferrin index >1.0 (serum iron/transferrin)

33. Selenium An antioxidant mineral; helps prevent skin damage from sun exposure Found in high amounts in Brazil nuts Deficiency related to cardiomyopathy (a form of heart disease), loss of muscle strength(Beck et al., 2007), and found with a form of anemia(Semba et al., 2007) Toxicity found with hair loss, defects of fingernails and toenails, anorexia, dermatitis, depression, organ damage, and central nervous system problems, including ataxia and respiratory disturbances(Kaprara and Krassas, 2006)

34. Zinc Critical for protein synthesis and cell division and function; part of 300 proteins; promotes stable DNA Needed for bone growth, wound healing, immunity, sexual development, smell acuity, taste perception, promotes normal vitamin A levels Part of 50 metabolic enzymes Found in whole grains (germ), oysters, crabmeat, organ meats, brewer’s yeast As a trace mineral, toxicity is possible; can lead to severe anemia due to low serum copper levels

35. Phytochemicals: “Chemicals of Life” Vitamin-like substances recognized since the 1990s Includes lutein (found in green leafy vegetables) Lutein: essential to prevent macular degeneration Includes lycopene (found in tomatoes) Lycopene controls prostate tumors Estimated 100 phytochemicals yet to be identified

36. Food Preparation Strategies to Preserve Vitamin and Mineral Content Store fresh produce to avoid wilting and/or drying out Cook foods in whole pieces, as possible, to decrease surface area for leaching of minerals into cooking water Steam or microwave to reduce leaching of minerals Cover open containers of juice to preserve vitamin C Avoid excessive stirring while cooking to minimize exposure of vitamin C to air Keep milk out of light to preserve vitamin B2 content

37. Fortification Versus Enrichment Fortify—make stronger (e.g., iron-fortified cereal) Enrich—replace after removal by processing (e.g., enriched white bread with vitamins B1, B2, B3)