ESS 3 Lecture Notes - Lecture 8: Folic Acid, Riboflavin, Dementia
Vitamins
Vitamins: organic compounds that occur naturally in common foods
➔Micronutrients (needed in small quantities)
➔ Essential nutrients (must be consumed in the diet to meet the body’s needs)
➔Are not a source of energy (calories)
◆Needed to extract energy from macronutrients
➔Blood boosters
◆Optimize blood health
➔Tissue guardians
◆Helps keep body structures healthy
➔Antioxidants
◆Helps protect against oxidative damage
Vitamins are classified according to their solubility
➔Fat-soluble: A, D, E, K
◆Excess intake stored
◆Long-term body storage
◆Deficiency unlikely
◆Higher risk of toxicity because of long-term storage
◆Less frequently needed
◆Most have pro-vitamins
➔Water-soluble: B, C, choline
◆Excess intake excreted
◆Short-term body storage
◆Deficiency likely
◆Lower risk of toxicity due to ability to excrete it
◆Most frequently needed
➔Difference: how they are absorbed and transported in body
◆Affects wherever they are stored
Fat-soluble vitamins
➔Absorbed in small intestine (leave in chylomicrons)
➔Insoluble in water and dissolve in lipids
➔Small amounts needed
➔Stored in tissue
➔Present in fatty portions of food
Vitamin A: vision and eye health
➔Animal source: retinol
◆More readily absorbed
➔Plant source: beta-carotene
◆Yellow, orange, red-pigmented fruits and vegetables
◆Important role as a phytochemical with antioxidant properties
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Vitamin D: bone growth
➔Sunshine vitamin
◆People who are more likely to synthesize adequate prohormone D live south of
the 33rd parallel and are outdoors when sunlight is most intense
➔Found in fatty acids, fish liver oils and fortified milk
◆Does not occur naturally in many foods besides fish
➔Needed for:
◆Increasing calcium and phosphate absorption
◆Reducing urinary calcium excretion
➔Must be activated in the kidneys and liver to fulfill its biological functions in the body
➔Deficiency can cause bone diseases
Vitamin E
➔Found in nuts and oils (almonds)
➔Protects the fatty components of our cells from oxidation
◆Protects LDL’s, red blood cells, and cells of lungs
➔Critical for normal fetal development of nerves and muscles
➔Less likely to be toxic than vitamins A and D because it is secreted less
Antioxidants: chemicals that protect cells against damage from oxidation
◆Vitamin E, A, C, beta-carotene, selenium
● E and C work by stabilizing free radicals and stopping damage to our
body
◆Prevent or repair damage caused by oxidation
● Oxidation results in the production of harmful byproducts called free
radicals which damage cells
○ Damage LDL’s, cell proteins, and DNA
○ Causes body to age and linked to disease
➔Free radicals: highly unstable atoms
◆Many metabolic processes involve oxidative reactions that produce harmful free
radicals
● Produced by oxidation reactions in cells
● Also produced by UV, toxic substances, pollution
Vitamin K: blood clotting and bone formation
➔Significant amount is produced by intestinal bacteria
◆Dietary sources: leafy greens, fruits, cheeses, oils
➔Key role in blood clotting
◆Needed in synthesis of protein for blood clotting
● Deficiency can cause uncontrolled bleeding
◆Bone metabolism
◆Modifies bone proteins
➔Deficiency
◆Primary deficiency is rare
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Vitamins: organic compounds that occur naturally in common foods. Essential nutrients (must be consumed in the diet to meet the body"s needs) Are not a source of energy (calories) Higher risk of toxicity because of long-term storage. Lower risk of toxicity due to ability to excrete it. Difference: how they are absorbed and transported in body. Absorbed in small intestine (leave in chylomicrons) Insoluble in water and dissolve in lipids. Important role as a phytochemical with antioxidant properties. People who are more likely to synthesize adequate prohormone d live south of the 33rd parallel and are outdoors when sunlight is most intense. Found in fatty acids, fish liver oils and fortified milk. Does not occur naturally in many foods besides fish. Must be activated in the kidneys and liver to fulfill its biological functions in the body. Protects the fatty components of our cells from oxidation. Protects ldl"s, red blood cells, and cells of lungs.
