Thick hair indicates healthy hair. It is also a good indicator of the general well being of the whole person. Hair may lose its thickness due to several conditions like hair loss, splitting, brittleness, etc. All these conditions indicate unhealthy hair which is not just unpleasant to look at but also detrimental to a person's health in the long run.

Thickness of the hair is determined by many factors: genetic, general health condition, external environment, stress levels and emotional balance of the person and so on. While there are several reasons for hair loss, thickness of the hair is very difficult to restore even by correcting these factors. Hence it is very important to maintain the health of the hair throughout.

Just like the rest of the body, hair's health is also determined by the kind of food we take. The body takes the required nutrients from the food we consume hence it is very important that we take a diet that is rich in vitamins, minerals, and proteins. Vitamins help the body in effective metabolism to break the fats and carbohydrates into energy and to supply this energy to the whole body. When the body does not receive the essential nutrients, or when it fails to absorb the nutrients from the food, the effect is first shown on the skin, hair and fingernails.

The necessary vitamins that aid in promoting thick hair are: vitamin A (produces healthy sebum in the scalp), vitamin C (antioxidant), vitamin E (improves scalp circulation), Biotin (produces Keratin), Inositol (keeps hair follicles healthy), Niacin (promotes scalp circulation) and pantothenic acid, Para-Aminobenzoic Acid, vitamin B6 and vitamin B12 that prevent graying and hair loss. There are several products in the market today in the form of shampoos, oils, conditioners, sprays and other applicants that can be put on externally for improving the health of the hair. These products contain necessary vitamins, protein and mineral supplements that are believed to enter the skin on the scalp and provide proper nourishment to the hair. Apart from these, hair vitamin supplements are also available in tablet/capsule form for internal ingestion. There are numerous companies that are developing hair vitamin products from herbal and traditional ingredients like ginseng, jojoba, green tea, He Shou Wu etc, which are believed to contain the essential vitamins for promoting healthy hair. The most common food-based sources of these vitamins are: citrus fruits, green vegetables, fruits like pineapple, strawberries, kiwi, potatoes, green peppers, vegetable oils, soybean, raw seeds, dried beans, wheat germ oil, brewer's yeast, whole grains, eggs, liver, rice, milk, fish, turkey, chicken and red meat. Today, almost all hair care products advertise the presence of a necessary vitamin in their products that would make the hair thicker.

There are several websites that provide information about hair vitamin products. There are also exclusive stores that specialize in hair vitamin products. However, it is better to consult a physician before using these products to understand the exact condition of the hair so that the right products can be used.