HNSC Unit 7

Vitamins

Vitamins

• essential, non-caloric organic nutrients

• needed in very small amounts

• cofactors (helpers) in cell functions

Fat Soluble Classification

• vitamins A, D, E, K

  • dissolve in lipid

  • require bile for absorption

  • transported in lymph

  • stored in tissues

  • may be toxic in excess

  • caution with supplements

Vitamin A - Essential For:

• gene expression

• immune defenses

• vision

• bone growth

• reproduction

• epithelial tissue

• chemical forms: retinol

• precursor: B-carotene

Vitamin A - Beta-Carotene

• precursor

• plant sources: brightly coloured

• effective antioxidant

• may reduce risk of chronic diseases

Vitamin A - Food Sources

• beef liver, fish oil, milk, dark green and orange veggies

Vitamin A Deficiency Symptoms

• blindness

• impaired bone growth, decayed teeth

• impaired immune function

• keratin lumps on skin

Vitamin A Toxicity Symptoms

• stunted growth, muscle/bone soreness, headaches

• edema, fatigue

• anorexia, nausea

• skin disorders, enlarged spleen

• liver damage, rashes, itching

Other Forms of Vitamin A

• retinoic acid as a drug, directly applied to the skin results in rapid turnover of skin cells

• retin-a: acne

• highly toxic: serious birth defects if taken during pregnancy

Vitamin D - Functions

• chemical name: cholecalciferol

• regulation of blood calcium and phosphorus levels, important for bone formation

• workings of the brain, heart, stomach, pancreas, skin and reproductive organs

• immune system (stimulates maturation of cells)

• functions as a hormone

Vitamin D - Sunlight and Food Sources

• fortified milk and margarine, eggs, butter, fish

• UV radiation converts precursor molecule in skin

  • MB latitude: april to oct.; use liver sources in winter

  • duration specific to skin colour

  • time of day: midday hours provide max direct sun exposure

Vitamin D Deficiency

• rickets: bone disease in children

• osteomalacia: bone disease in adults

Vitamin D - Research

• deficiency may increase risk of high blood pressure, some cancers, T1 diabetes, heart disease, inflammatory bowel disease, MS

• risk increases with age

Vitamin D - Toxicity

• often due to self-prescribing high-dose supplements

• symptoms:

  • appetite loss, nausea, increased thirst, severe depression

  • long term:

    • calcium deposits in heart, blood vessels, lungs and kidneys = death

Vitamin E - Functions

• chemical name: tocopherol

  • alpha (gold standard), beta, delta, gamma

• acts as antioxidant in cell membs.

• integrity of cells exposed to high O conc.

• widespread in foods

• destroyed by heat processing

Vitamin E Deficiency

• is rare

  • erythrocyte hemolysis in premature infants born before 30 weeks

  • weakness, impaired reflexes (muscle and nerve function) → oxidative damage

  • caused by fat absorption and storage problems

Vitamin E - Toxicity

• is rare

• nausea, fatigue,, GI distress, blurred vision

• increase risk bleeding when combines with anticoagulant meds

Vitamin K Functions

• blood clotting and bone protein synthesis

• anticoagulant meds interfere with Vit. K and blood clotting

Vitamin K Sources

• bacterial production in colon

  • affected by absorption problems

  • antibiotics decrease production

• green leafy veg., cabbage family

• liver, eggs, milk

• beans, legumes

Vitamin K - Deficiency and Toxicity

• rare:

  • newborns needs supplements due to sterile GI tract

  • taking meds that kill bacteria

  • fat absorption problems

  • easy bruising, hemorrhaging

• in excess rare:

  • in infants or during pregnancy: taking supplement

  • symptoms: jaundice → RBCs break and release pigment (bilibrium)

Water Soluble Vitamins

• Vitamin C, B

  • dissolve in water

  • are easily absorbed and excreted

  • are not stored extensively in tissues

  • seldom toxic levels

Vitamin C - Functions

• maintenance of collagen/CT (bones, teeth, skin, tendons)

• antioxidant protection

• supports immune function

• promotes iron absorption

• restores Vit. E to active form

Vitamin C - Food Sources

• fruits (citrus), veggies

• vulnerable to heat and destroyed by Oxygen

Vitamin C - Deficiency

• scurvy

• loss of appetite, growth cessation, weakness, frequent infections, bleeding gums, tiny red dots on skin, swollen wrists and ankles

Vitamin C - Toxicity

• low risk

• problems if >2g/day

• can interfere with anticoagulation meds

• hemochromatosis (too much iron) → should avoid vitamin c supplements

The B Vitamins

• acts as coenzymes

• involved in energy metabolism

• thiamin (B1)

• riboflavin (B2)

• niacin (B3)

• pantothenic acid (B5)

• pyridoxine (B6)

• biotin (B7)

• Folate (B9)

• cobalamin (B12)

Thiamin B1

• energy metabolism in all cells

• nerve processes and muscles

• widespread: pork, legumes, seeds, whole grains

• alcohol impairs thiamin absorption and speeds up excretion

Riboflavin B2

• energy metabolism in all cells

• supports vision and skin health

• enriched grains, milk products, veggies, meats, eggs

Niacin B3

• energy metabolism in all cells

• tryptophan can be converted to niacin

• enriched and whole grains, leafy green veggies and baked products, milk products, meat, fish, eggs

• may be used to treat blood cholesterol

Folate B9

• synthetic form = folic acid

• new cell synthesis

• growth, early embryonic life and tissue turnover

• leafy green veggies, fruit, legumes, seeds, liver, milk may enhance absorption

Cobalamin B12

• myelin sheath in nerve fibers (nerve transmission)

• coenzyme in energy and amino acid metabolism

• animal origin, fermented products

• folate and B12 depend on each other for activation

• needs intrinsic factor for B12 absorption

Pyridoxine B6

• AA and protein metabolism

• FA metabolism

• Synthesis of hemoglobin and neurotransmitters

• immune function and steroid activity

• critical for fetal development

• leafy green, fruits, meat, whole grains

Biotin B7

• cofactor in energy metabolism

• in lots of food

• deficiency: avidin in egg whites binds biotin denatured by cooking

Pantothenic Acid B5

• energy metabolism

• rare deficiency

• in lots of food

Approved Products Have:

• natural product number (NPN)

• drug identification number

  • homeopathic medicine (DIN-HM)