Genetics certainly contribute to determining your skin complexion. But your gene pool will do very little good if your diet is grossly deficient in certain elements – the vitamins, minerals and proteins that your body needs.
There are decades of misconceptions and myths that exist about the effects of certain foods on your skin – some factual, some not. Do you remember being told as a kid that junk food gives you pimples? Many experts now say that greasy foods and chocolates will not directly give you pimples as previously thought; but clearly it will affect the health and ability of the body to detoxify itself. It is also well known that there are some foods that can encourage the natural cleansing process of the skin.

The Necessity of Vitamins
Studies show that the vitamins A, C, E, K, and B complex all help improve skin health and appearance. Here's how.
Vitamin A: If your vitamin A levels are up to snuff from the foods you eat, adding more probably will not do much more for your skin. That said, if those levels drop even a little below normal, you are likely to see some skin-related symptoms, including a dry, flaky complexion. That is because vitamin A is necessary for the maintenance and repair of skin tissue. Without it, you will notice the difference. Vitamin A was first discovered in 1913 and today it is known to be important for several health issues. Vitamin A not only contributes to proper cell growth and repair, particularly of skin cells, but is also essential for strengthening night vision, assisting bone growth, and regulating the immune system. A deficiency of vitamin A can not only lead to dry skin, but also to broken fingernails and dry hair and eyes. Skin problems which result in a buildup of scaly or horny skin (keratinising), such as eczema and psoriasis, may benefit from vitamin A supplementation.
Vitamin A can be found in a number of healthy foods including carrots, egg yolks, peas, apricots, kale, spinach, broccoli, pumpkin, squash, sweet potatoes and oranges, apricots, peaches, mango, cantaloupe and cherries. Liver, cod oil, milk and egg yolks are also a rich source of vitamin C.
Vitamin C: Among the most important new dermatologic discoveries is the power of vitamin C to counter the effects of sun exposure. It works by reducing the damage caused by free radicals, a harmful byproduct of sunlight, smoke and pollution. Free radicals gobble up collagen and elastin, the fibers that support skin structure, causing wrinkles and other signs of aging.
Vitamin E: Vitamin E is believed to promote great skin because it is truly one of the most powerful antioxidant vitamins known to heal, hydrate and protect. Snack on nuts, such as hazelnuts and almonds.
Research shows that, like vitamin C, this potent antioxidant helps reduce the harmful effects of the sun on the skin. According to studies published by the AAD, taking 400 units of vitamin E daily appeared to reduce the risk of sun damage to cells as well as reduce the production of cancer-causing cells.
Vitamin B Complex. Without adequate amounts of B complex vitamins, you may end up with dermatitis (an itchy, scaly skin reaction) or sometimes even hair loss. Even a mild deficiency causes symptoms.

The Necessity of Minerals
Health experts agree that most of us do not need to supplement our mineral intake; we get enough in our daily foods. But they certainly play a role in the condition of the skin.
Iron: Apart from vitamins, your diet should also include minerals. Iron makes the blood healthy. Consequently, it imparts a healthy, pink glow to your skin. 
Selenium: The antioxidant mineral selenium preserves tissue elasticity and slows down the aging and hardening of tissues caused by oxidation.
Copper: Together with vitamin C and the mineral zinc, copper helps to develop elastin, the fibers that support skin structure from underneath.
Zinc: Linked to a connection with acneic skin, studies have suggested that acne itself is a symptom of a zinc deficiency. Taken internally or used topically, zinc works to clear skin by taming oil production and may be effective in controlling the formation of acne lesions.
Silica: Silica is a mineral which is found in bones, artery walls, connective tissue, hair, nails and skin. The main action of silica is to provide strength and flexibility.

The Final Outcome
Your skin is the fingerprint of what is going on inside your body; and you are the role model for healthy, beautiful skin. Take care of yourself and practice what you preach to your clients!