If you find the choice of health supplements totally confusing, Catherine Beattie's A-Z guide will help you select some to suit your individual needs and lifestyle. 

Vitamin A (Retinol)

An important antioxidant that helps protect cells and builds up resistance to infection. Essential for healthy skin and mucous passages and for night vision. Large doses of vitamin A are sometimes prescribed to treat acne and psoriasis but must be medically supervised as excessive amounts are toxic. The Recommended Daily Allowance (RDA) is 800mcg and maximum intake from supplements such as fish oils and multivitamin tablets is 2,300mcg daily. Vitamin A supplements should be avoided in pregnancy, as they may cause foetal damage.

Good food sources: fish, meat and dairy products.

Agnus castus

A Mediterranean herb used for the relief of premenstrual problems and menopausal symptoms. Thought to act on the pituitary gland and areas of the brain controlling hormone production and activity. Users of the contraceptive pill and HRT may find the herb incompatible with synthetic hormones, so should seek advice from a qualified herbalist before using.
Aloe vera

The transparent gel from the leaves of the succulent plant is used to heal and soften skin. Can be taken in capsule or liquid form to improve digestion or as a laxative. Aloe vera also makes a good tonic as its strong antiviral properties boost the immune system.

Amino acids

A group of 21 nutrients that build the proteins that make up our tissues, organs and enzymes triggering the millions of chemical reactions within us every second. Each amino acid has its own therapeutic effects. Eight of these nutrients are labelled "essential", which means we must obtain them from our diet because they are not produced in adequate quantities in the body, unlike the non-essential amino acids. Research into amino acids is one of the most exciting areas of nutritional medicine.

Good food sources: protein foods (especially pork and chicken), eggs, dairy produce, oats, eggs, beans, garlic, pulses, nuts and seeds.

Antioxidants

The name for vital nutrients that protect the body's cells from harmful 'free radicals' (highly unstable and reactive molecules created when oxygen combines with food to produce energy). Pollution, smoking, stress and other environmental factors increase free radical numbers, causing damage to our cells and tissues. The main antioxidant nutrients are vitamins A, C and E, beta-carotene and selenium. Zinc, gingko biloba, coenzyme Q10 and certain amino acids also contain valuable antioxidant properties.

Good food sources: fish, meat, eggs, dairy produce, bread, pasta and cereals, nuts, pulses, fresh fruit and vegetables.

Vitamin B complex

The B complex consists of eight individual B vitamins each with its own properties - B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B12 (cobalamin), B9 (folic acid) and biotin (coenzyme R). Chloline and inositol are related nutrients. B vitamins tend to occur and work as a group in the same kind of foods, so individual doses should always be taken with a B complex supplement to avoid any imbalance. We need a good supply of B complex vitamins to release energy from food, for the health of the nervous and digestive systems, and to keep the skin, hair and nails in good condition. B vitamins are easily destroyed by cooking and sunlight and are not stored in the body, so must be obtained from our daily food intake.

Good food sources: whole grains, cereals, milk, eggs, yeast, liver, meat, poultry, fish and leafy green vegetables.

Bach Flower Remedies

Devised by a medical doctor and homeopath, these 38 plant and flower remedies are used to treat various emotional states. Each remedy is a complete system of healing and is safe, effective and completely natural. Sold in 10ml dropper bottles at health food stores and pharmacies - just add two drops to a glass of water glass or drop directly onto the tongue. The universally popular Rescue Remedy is available in a large size and also as a cream.

Beta carotene - pro-vitamin A

This unique antioxidant nutrient provides the bright yellow, green and orange pigment in plants. It 'mops up' excess free radicals in the body and protects the skin from ultraviolet damage. If we are deficient in vitamin A, our bodies divert beta carotene into making it - 1mg beta carotene making 167mcg of vitamin A. Many vegetarians and vegans rely on beta carotene for their vitamin A intake. The nutrient is stored in fatty tissue and is non-toxic even in high intakes. We need about 10-15mg daily.Good food sources: brightly coloured fruits and vegetables.

Borage (starflower oil)

A rich source of gamma linolenic acid (GLA), this unusual fatty acid has no normal dietary source and the body makes it from linoleic acid in vegetable oils. GLA has a regulatory effect on the immune system, the circulation and the menstrual cycle. Interestingly, the chemical structure of borage is quite different from that of evening primrose oil, another valuable source of GLA. Borage supplements may be taken singly or combined with evening primrose oil.

Boron

A trace mineral found in our bones. New research suggests that boron may slow down calcium and magnesium loss from the bones of menopausal and post-menopausal women. Boron also benefits some forms of arthritis. Recommended supplementation is 3mg on a daily basis.