Week 15: Vitamin and Nutritional Supplement

Vitamins

Required for normal body metabolism, growth, and development; components of enzyme systems that release energy from carbohydrates, proteins, and fats; required for formation of RBCs, nerve cells, hormones, genetic material, bone, and other tissues.

Fat-soluble vitamins

Vitamins A, D, E, and K; stored in the body when taken in excess; absorbed from the intestine with dietary fat, requiring bile salts and pancreatic lipase.

Water-soluble vitamins

B-complex vitamins and vitamin C; not stored in the body and are rapidly eliminated.

Patient education: Who may need vitamin supplements?

Pregnant women, smokers, those who ingest large amounts of alcohol, people with impaired immune systems, and the elderly.

Patient education: Natural vs. synthetic vitamins

Chemically identical; body uses them the same way; natural vitamins are more expensive with no evidence of being better.

Vitamin A dietary sources

Liver, milk, butter, cheese, cream, egg yolk, fortified milk, margarine, ready-to-eat cereals; beta-carotenes in spinach, kale, carrots, sweet potatoes, mango, broccoli, etc.

Vitamin A toxicity

Excessive amounts stored in body; high doses can cause headaches, diarrhea, nausea, loss of appetite, dry/itching skin, elevated blood calcium; may cause birth defects if taken in excess during pregnancy.

Vitamin E dietary sources

Vegetable oils, margarine, salad dressing, nuts, seeds, wheat germ, dark green vegetables, whole grains, fortified cereals.

Vitamin K dietary sources

Spinach, brussels sprouts, broccoli, cabbage, cauliflower, Swiss chard, lettuce, collard greens, carrots, green beans, asparagus, eggs.

Vitamin K and warfarin

Intake of vitamin K-containing foods should remain constant during warfarin therapy; report any vitamin K use to healthcare provider.

Vitamin B1 (thiamine) sources

Whole grain/enriched breads and cereals, liver, nuts, wheat germ, pork, dried peas and beans.

Vitamin B3 (niacin) sources

All protein foods, whole grain/enriched breads and cereals.

Vitamin B6 (pyridoxine) sources

Meats, fish, poultry, fruits, green leafy vegetables, whole grains, dried peas and beans.

Niacin administration tip

Take with or after meals or at bedtime (except timed-release) to decrease stomach irritation; sit/lie down for ~30 minutes after dose due to vasodilation effects (flushing, dizziness).

Vitamin B12 sources

Meat, fish, poultry, shellfish, milk, dairy products, eggs, fortified foods; not in plant sources; strict vegans at risk for deficiency.

Folic acid sources

Liver, okra, spinach, asparagus, dried peas and beans, seeds, orange juice; breads, cereals, grains are fortified.

Vitamin C dietary sources

Citrus fruits/juices, red/green peppers, broccoli, cauliflower, brussels sprouts, cantaloupe, kiwi, strawberries, tomatoes.

Vitamin C effect on iron

Improves absorption of iron.

Patient teaching for mineral supplements

Take only on healthcare provider's advice; all minerals are toxic in excess; iron and calcium often needed as supplements in women and children.

Iron administration guidelines

Take with/after meals with 240 mL fluid; do not crush/chew slow-release forms; dilute liquids, use straw, rinse mouth; stools may turn dark green/black; avoid taking with caffeine (space at least 2 hours apart).

Potassium administration guidelines

Mix solutions/effervescent tablets with at least 120 mL water/juice; do not crush/chew slow-release; take after meals initially to decrease gastric irritation.

Tube feeding guidelines

Give with patient sitting; ensure correct tube placement; use room temperature formula; do not exceed 500 mL per feeding including flush; administer over 30-60 minutes.

Nursing assessment for nutritional deficiencies

Assess eating patterns, weight/BMI, symptoms/disease/treatments that interfere with nutrition; deficiencies more common than excesses.

Vitamin deficiency risk factors

Increased needs during infancy, pregnancy, lactation, fever, hyperthyroidism, illness; more common in poor, elderly, chronically ill, alcoholic.

Mineral-electrolyte deficiency risk factors

Loss via gastric suction, polyuria, diarrhea, excessive perspiration; many drugs (diuretics, laxatives) influence gains/losses.

Nursing lab assessment

Check CBC for low RBCs, hemoglobin, hematocrit (iron deficiency); check serum electrolytes (sodium, potassium, chloride, bicarbonate).

Coenzyme Q-10 interaction

Structurally similar to vitamin K2; may antagonize warfarin effects.

Cranberry juice therapeutic use

Prevents UTI by inhibiting bacterial adhesion; effective in teens/20s and elderly women; may increase INR in warfarin patients.

Garlic therapeutic use

Used to reduce triglycerides, LDL, raise HDL, reduce BP, suppress platelet aggregation; must be raw for allicin effect; has antiplatelet effects.

Melatonin primary use

Treatment of insomnia; also used for shift work disorder, winter depression, tardive dyskinesia; no habituation/dependence; contraindicated in hepatic disease.

St. John's wort use and risk

Used for mild to moderate depression; induces cytochrome P450 and P-glycoprotein; intensifies serotonin effects; interacts with many drugs.

Harmful supplements examples

Kava (severe hepatic damage); Ma huang/ephedra (elevates BP, stimulates heart and CNS).

Key take-home point about supplements

Not a quick fix for poor diet; carry risk of adverse events; healthy dietary intake is most valuable, but supplements may have their place.