Vitamins, Supplements, and Safety Considerations

Vitamin A

Night vision, cell growth and maintenance, skin health. Toxicity can cause headaches, peeling skin, bone thickening.

Vitamin D

Calcium absorption, bone and tooth health, heart and nerve function. Toxicity can lead to kidney failure, metastatic calcification, anorexia.

Vitamin E

Protection of cells (including skin and brain), formation of blood cells.

Vitamin K

Blood clotting, bone growth. Can counteract blood clotting medications, reducing their efficiency.

Vitamin B1

Carbohydrate metabolism, heart, nerve, and muscle function.

Vitamin B2

Fat and protein metabolism.

Vitamin B3

Carbohydrate and fat metabolism. Toxicity can cause red, itching skin with tingling.

Vitamin B6

Enzyme assistance in amino acid synthesis. Toxicity can lead to peripheral neuropathy.

Vitamin B12

Protein and fat metabolism, nerve-cell maintenance, cell development.

Vitamin C

Immunity, iron absorption, structure of bones, muscle, and blood vessels.

St. John's wort

Treatment for depression, anxiety, and sleep disorders. Some studies found it ineffective (similar results to placebo); no long-term safety studies.

Black cohosh

Relief of menopause symptoms (hot flashes, night sweats, headaches, heart palpitations, mood changes). Large doses can cause vomiting, dizziness, headaches; recommended for less than 6 months.

Melatonin

Sleep regulation, combat aging (studies support sleep regulation, not anti-aging). Can cause drowsiness, headaches; may interfere with conception.

Willow bark

Pain relief (aspirin's main ingredient comes from willow bark). Do not exceed 240 mg/day; not safe for those who cannot tolerate aspirin.

Glucosamine sulfate

Promote healthy cartilage formation to maintain or replace wear and tear on joints. No safety concerns; recent studies found it no more effective than placebo in knee osteoarthritis.

Gingko biloba

Improve memory and mental function by increasing blood flow to the brain. Extremely high doses can cause nausea, vomiting, diarrhea.