Vitamin A is usually used for improving poor night vision, dry skin, and it can help acne. The usual dosage is 1000 – 2000 ug. A word of warning though – being a fat soluble vitamin the excess is stored in our body, and too much vitamin A can cause side effects. Also, an excess of vitamin A can actually make acne worse.

The B vitamins work together as a group and have many uses in the body. B supplements are usually recommended for smokers, those suffering from stress or nervous conditions, and people who drink regularly.

Vitamin B6 is often taken for PMS and fluid retention, at the dose of 10 mg per month.

Vitamin B12 is recommended for vegans as it tends to be lacking in their diet. The dose is 100 ug.

Folate is recommended for pregnancy to prevent neural tube birth defects, and also for women trying to conceive. The dosage is 400 ug.

Vitamin C is great for the skin, has antioxidant properties and is thus good for smokers and drinkers, as well as anyone suffering from stress. The recommended dose is 250 to 1000 mg per day.

Vitamin D is usually synthesized by exposure to sunlight, and it is often a cofactor in calcium supplements because it helps the calcium be absorbed by the body. D supplements are usually only needed by the elderly or those unable to go outside. Dosage is quite small, at 5 to 10 ug per day.

Vitamin E is an excellent antioxidant, good for skin problems like acne, wound healing, and as an accompaniment to essential fatty acid supplements like flaxseed and omega 3 fish oils. It helps prevent them being oxidized in the body. Dose is 275 mg per day.

Calcium supplements are recommended if you're not getting at least 1000 mg of calcium per day through what you eat. Women in particular have to watch their calcium intake. If there is a family history of osteoporosis, calcium supplements are also recommended. And it's great for insomnia.

Iron should not be taken unless you know you are deficient as it can build up in the body and become toxic. If you are pregnant, have anemia, or heavy periods, get your iron levels checked by a doctor to see if you need to take iron. Dosage is 14 mg per day.

Magnesium is great for period pain, insomnia and stress. It is usually a cofactor in good calcium supplements as it helps the calcium be absorbed better by your body. Daily dose is 150 mg.

Zinc is great for the immune system, as well as poor appetite and acne. Zinc helps speed up wound healing too. Dosage is 7 to 15 mg.

Selenium is an antioxidant that is used for arthritis, cancer and HIV patients. Dosage is 100 to 200 ug per day.

References: Judith Wills, The Food Bible