Extreme deficiencies of minerals and vitamins are uncommon in the developed world. On the other hand, research shows that slight deficiencies in some nutrients could be fairly common.
If you do not consume a nutritious assortment of foods, certain supplements could help you get sufficient quantities of essential nutrients. So, using supplements to provide these essential minerals and vitamins might be a good idea.
The easiest method to support your nutrition and health would be to use a broad mineral and multivitamin supplement giving you a wide range of nutrients. However, no nutritional supplement must be considered to be an alternative to a healthy and varied diet.
How vitamins and dietary supplements are stored can have an effect on the quality. High humidity found in bathrooms as well as kitchens may be degrading the vitamins and dietary supplements kept in those rooms, whether or not the lids are on tight, research has shown.
Crystalline substances, such as vitamin C, some forms of vitamin B and other nutritional supplements, are susceptible to a process known as deliquescence, whereby humidity results in a water-soluble solid to dissolve. Storing those supplements far away from warm, humid environments will help ensure their effectiveness.
Adequate intake of B complex vitamins such as biotin, niacin, cobalamin and pantothenic acid are essential for healthy hair and skin.
(Vitamin B7) Biotin and Hair
Biotin is an extremely important vitamin for hair health. Biotin is believed to make hair grow stronger and is one of the main ingredients in many hair care products.
Research has shown that biotin supplementation can improve hair problems in people with uncombable hair syndrome. This syndrome is characteristic of slow growing hair that can’t be combed flat. The biotin treatment was effective in increasing strength of the hair roots, and in accelerating the growth rate of hair. 
(Vitamin B5) Pantothenic Acid and Hair
Panthenol is the alcohol of pantothenic acid. Panthenol is the major constituent of several oral preparations claiming to enhance hair growth.
Research has shown that a combination supplement containing vitamin B5 improved hair growth in women with hair loss.
(Vitamin B12) Cobalamin and Hair
There have been claims by some dieticians that vitamin B12 can promote hair growth. But any evidence to substantiate these claims is anecdotal. Even so, it is well established that vitamin B12 is important for the health of hair and skin. Vegetarians are at risk of vitamin B12 deficiency as it’s found only in animal foods.
Vitamin D and Hair
Research has established an association between vitamin D deficiency and hair loss. The vitamin D receptor is crucial to hair growth, rather than vitamin D itself. Vitamin D is what activates the receptor.
Research has suggested that vitamin D can help stem cells create new hair follicles.