Vitamin D
Sources
1. synthesized by the skin, activated by the liver and kidneys
2. fortified milk, bread, juices, and other fortified foods, oily fish
and fish oils
Uses
1. increases absorption of calcium and phosphorous by small intestine
2. assists bone maintenance through bone matrix turnover
3. increases kidney reabsorption of calcium
4. increased mobilization of calcium from bones
5. affects calcium transport in many cells (brain, bone, pituitary)
6. part of therapy for osteoporosis
Recommended dietary intake
1. 5 micrograms per day
2. more than 5 micrograms per day for the elderly
Causes of deficiencies
1. inadequate eating
2. low fat diet
3. less sun exposure, less skin synthesis, and less kidney activation
4. in women, decreased estrogen and possible decreased parathormone levels
cause less activation by the kidney
5. laxatives like mineral oil bind vitamin D in intestine cause decreased
absorption
6. anti-inflammatory steroid therapy (e.g., for osteoarthritis)
Results from deficiencies
1. decreased calcium absorption by the small intestine
2. increased risk of osteoporosis
Causes of excesses
1. vitamin supplements
2. vitamin D therapy for osteoporosis
Results from excesses
1. hypercalcemia causes calcium deposits
2. hypercalciuria causes urinary stones
3. weakness, brain malfunctions
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Vitamin E
Sources
1. vegetable oils, peaches, asparagus
Uses
1. antioxidant against harmful effects of free radicals and other oxidants,
ex. lungs, vitamin A, double bonds in unsaturated fatty acids (e.g., cell
membranes)
2. decreases risk of cancer
3. important for iron metabolism, maintaining nerve tissue, immune function
4. must be replaced since vitamin E molecules are destroyed when countering
oxidizing agents (reduces oxidizing agents)
Recommended dietary intake
1. 8-10 mg per day
Causes of deficiencies
1. inadequate eating
2. smoking destroys vitamin E in lungs
Results from deficiencies
1. hemolysis by oxidizing agents altering fatty acids in cell membranes
cause anemia
2. nervous system abnormalities
Causes of excesses
1. supplements
Results from excesses
1. hemorrhaging from decreased vitamin K activity
2. nervous system malfunction cause headache, fatigue, nausea
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Vitamin K
Sources
1. synthesized by large intestine bacteria
2. green leafy vegetables, peas, green beans, liver
Uses
1. synthesis of blood clotting materials (e.g., prothrombin) by the liver
Recommended dietary intake
1. 65-80 micrograms per day
Causes of deficiencies
1. antibiotics killing large intestine bacteria
2. low fat absorption
3. mineral oil laxatives block absorption
Results from deficiencies
1. bruising
2. bruising, anemia from bleeding
Causes of excesses
1. supplements
Results from excesses
1. anemia and jaundice
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Thiamin
Sources
1. thiamin-enriched foods, pork, whole grains
Uses
1. assists in getting carbohydrate fragments into the Krebs cycle and with
other Krebs cycle reactions to get energy from amino acid fragments
2. helps synthesize neurotransmitters (e.g., acetylcholine)
Recommended dietary intake
1. 1.1-1.5 mg per day
2. 1.0-1.2 mg per day for the elderly
Causes of deficiencies
1. inadequate eating
2. alcohol reduces thiamin absorption and use
3. regular consumption of tea, which contains thiamin antagonists
Results from deficiencies
1. low energy causes weakness
2. brain and neuron malfunction
Causes of excesses
1. rare
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Riboflavin
Sources
1. dairy products
Uses
1. make FAD for energy reactions in mitochondria (carbohydrate, fatty acid,
and amino acid breakdown)
Recommended dietary intake
1. 1.3-1.7 mg per day
2. 1.0-1.2 mg per day for the elderly
Causes of deficiencies
1. low dairy products in diet
2. alcoholism causing poor diet
3. estrogen therapy
Results from deficiencies
1. inflammation of the mouth and skin
2. vision problems
Causes of excesses
1. none
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Niacin
Sources
1. mushrooms, meats, fish, grains, peanuts
Uses
1. make NAD and NADH to get energy from carbohydrates, fatty acids, and
amino acids
2. used in many synthesis reactions for lipid and proteins
3. high doses lowers blood cholesterol
Recommended dietary intake
1. 15-19 mg per day
2. 13-15 mg per day for the elderly
Causes of deficiencies
1. inadequate eating
Results from deficiencies
1. weakness
2. brain malfunction, dementia
3. skin rashes
4. diarrhea
Causes of excesses
1. supplements to lower blood cholesterol
Results from excesses
1. redness (vasodilation) and itching of the skin
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Vitamin B6
Sources
1. meat, fish, bananas, broccoli, spinach
Uses
1. used in many reactions to obtain energy and to manufacture molecules
2. converting one amino acid to another
3. synthesizing amino acids
4. synthesis of hemoglobin, WBCs, neurotransmitters (e.g., norepinephrine,
GABA, serotonin)
Recommended dietary intake
1. 1.6-2.0 mg per day
2. 2.0 mg per day for the elderly
3. increases recommended for alcoholics, smokers, women on estrogen therapy
Causes of deficiencies
1. inadequate eating
2. smoking
3. estrogen therapy
4. alcoholism causes decreased absorption and interconversion of vitamin
B-6 molecules, increased destruction of vitamin B6
Results from deficiencies
1. anemia
2. excess blood homocysteine
3. CNS malfunction
4. low immune response
5. poor cell and tissue maintenance and repair
Causes of excesses
1. supplements for any reason or to treat PMS in premenopausal women
Results from excesses
1. nerve damage
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Vitamin B12
Sources
1. meats, milk
Uses
1. assists folate for DNA and RNA synthesis
2. RBC synthesis
3. break down fatty acids for energy
4. maintaining myelin sheath
Recommended dietary intake
1. 2.0 micrograms per day
2. 3.0 mg per day for some elderly
Causes of deficiencies
1. inadequate eating
2. decreased stomach acid or intrinsic factor production
3. atrophic gastritis
4. small intestine disease
Results from deficiencies
1. anemia
2. excess blood homocysteine
3. poor nerve function
Causes of excesses
1. none
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Folate
Sources
1. fresh fruits, raw or lightly cooked green leafy vegetables, orange juice
Uses
1. synthesis of some amino acids and parts of DNA and RNA molecules
Recommended dietary intake
1. 180-200 micrograms per day
Causes of deficiencies
1. inadequate eating
2. alcoholism decreases folate absorption
3. decreased stomach acid may decrease absorption
4. overcooking vegetables
Results from deficiencies
1. poor cell reproduction
2. anemia from production of abnormal RBCs
3. abnormal CNS and digestive system functioning
4. hair loss
Causes of excesses
1. none
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Pantothenic acid
Sources
1. mushrooms, meats, most vegetables
Uses
1. synthesis of molecules and for transferring fragments into the Krebs
cycle (for energy and synthesis)
Recommended dietary intake
1. 4-7 mg per day
Causes of deficiencies
1. inadequate eating
Results from deficiencies
1. fatigue
2. digestive system discomfort
3. muscle cramps
4. increased risk of infection
Causes of excesses
1. none
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Biotin
Sources
1. cheese, egg yolks, cauliflower
2. made by intestinal bacteria
Uses
1. assisting entrance of molecular fragments into the Krebs cycle (energy
and synthesis)
Recommended dietary intake
1. 30-100 micrograms per day
Causes of deficiencies
1. inadequate eating
Results from deficiencies
1. inflamed skin
2. weakness
3. anemia
4. depression
5. digestive system discomfort
Causes of excesses
1. supplements
Results from excesses
1. unknown
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Vitamin C
Sources
1. citrus fruits, other fresh fruits, green vegetables
Uses
1. assists in protein synthesis, especially collagen synthesis
2. assist cell-mediated part of immune response
3. activated iron and other minerals that assist enzyme activities
4. anti-oxidant (e.g., protects lungs, reduces cancer risk)
5. neutralizes carcinogens from nitrates in foods
6. assists iron absorption
7. assists synthesis of many substances (e.g., norepinephrine, steroid
hormones, parts of DNA, thyroid hormone)
8. high levels reduce blood cholesterol and LDLs in some people
Recommended dietary intake
1. 60 mg per day
Causes of deficiencies
1. inadequate eating
2. smoking destroys vitamin C in the lungs
3. overcooking or washing foods
4. cancer
5. anti-inflammatory steroid therapy (e.g., for osteoarthritis)
Results from deficiencies
1. poor healing
2. edema
Causes of excesses
1. supplements
Results from excesses
1. diarrhea
2. excess iron absorption
3. urinary system stones
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Copyright 2020: Augustine G. DiGiovanna, Ph.D.,
Salisbury University, Maryland
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