Your skin is the first line of defense against the external environment. It is the largest organ in the body and is constantly protecting you from harm; for example, it can protect against mechanical or thermal injuries, excess water loss, UV irradiation and penetration of harmful chemicals, allergens and pathogens. So, to keep the skin functioning at its best, it's no surprise that nutrition, which delivers an adequate amount of some important micronutrients, play a key role.

If you're aiming for healthy and beautiful skin, you should pay particular attention to your micronutrient intake, especially Vitamins A, C, E, niacin, biotin, zinc, copper, selenium and iodine. Each of these micronutrients plays a key part in keeping skin looking well-maintained. Vitamin A, niacin, biotin, zinc and iodine all contribute to the maintenance of normal skin (1-8) and if you're not taking enough of these micronutrients, changes in the appearance of the skin can occur. These changes can be dry and itchy skin, which is a sign of iodine and Vitamin A deficiencies (1-8), scaly and inflamed skin shows deficiencies in biotin levels, and various types of rashes are a sign of niacin and zinc deficiencies (3-7).

The benefits of consuming Vitamins C, E, copper and selenium is the protection from oxidative stress (9-14). Oxidative stress refers to a state within your body where free radicals (harmful particles) outnumber the body's antioxidant defenses. The skin can be a major target for oxidative injury - exposure to UV rays or air pollutants can be the cause of this stress (15).   This in turn can lead to wrinkled or saggy skin (15,16) as prolonged exposure to free radicals overwhelms the skin's natural defense mechanisms.

Additionally, vitamin C contributes to normal collagen formation for the normal function of skin (10). Collagen is the main structural protein that provides strength and elasticity to your skin, but its production starts to decline around the age of 25 (17). Collagen levels can also decrease due to other factors such as smoking, sugar intake and sun exposure, which leads to the formation of wrinkles and sagging skin (18-21). There is no way to prevent age-related collagen loss, however you can help your body to stimulate the production of collagen by, for instance, ingesting food containing vitamin C (22).

To sum up, healthy skin is a great indicator of inner health. Topical products can help temporarily moisturise or clean the skin, but they will not help build or replace important skin components because their active ingredients just “sit on top of the skin”. In fact, having healthy skin starts from within. By consuming nutritionally dense foods that are rich in vitamins A, C, E, niacin, biotin, zinc, copper, selenium, and iodine, you are taking a key step to maintaining youthful-looking skin.

References

1. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to vitamin A and cell differentiation (ID 14), function of the immune system (ID 14), maintenance of skin and mucous membranes (ID 15, 17), maintenance of vision (ID 16), maintenance of bone (ID 13, 17), maintenance of teeth (ID 13, 17), maintenance of hair (ID 17), maintenance of nails (ID 17), metabolism of iron (ID 206), and protection of DNA, proteins and lipids from oxidative damage (ID 209) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1221
2. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to vitamin A (including β-carotene) and maintenance of normal vision (ID 4239, 4701), maintenance of normal skin and mucous membranes (ID 4660, 4702), and maintenance of normal hair (ID 4660) pursuant to Article 13(1) of Regulation (EC) No 1924/2006.  EFSA Journal 2010; 8(10):1754
3. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to niacin and energy-yielding metabolism (ID 43, 49, 54), function of the nervous system (ID 44, 53), maintenance of the skin and mucous membranes (ID 45, 48, 50, 52), maintenance of normal LDL-cholesterol, HDL-cholesterol and triglyceride concentrations (ID 46), maintenance of bone (ID 50), maintenance of teeth (ID 50), maintenance of hair (ID 50, 2875) and maintenance of nails (ID 50, 2875) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1224
4. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to niacin and reduction of tiredness and fatigue (ID 47), contribution to normal energy-yielding metabolism (ID 51), contribution to normal psychological functions (ID 55), maintenance of normal blood flow (ID 211), and maintenance of normal skin and mucous membranes (ID 4700) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010; 8(10):1757
5. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to biotin and energy-yielding metabolism (ID 114, 117), macronutrient metabolism (ID 113, 114, 117), maintenance of skin and mucous membranes (ID 115), maintenance of hair (ID 118, 2876) and function of the nervous system (ID 116) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1209
6. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to biotin and maintenance of normal skin and mucous membranes (ID 121), maintenance of normal hair (ID 121), maintenance of normal bone (ID 121), maintenance of normal teeth (ID 121), maintenance of normal nails (ID 121, 2877), reduction of tiredness and fatigue (ID 119), contribution to normal psychological functions (ID 120) and contribution to normal macronutrient metabolism (ID 4661) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8(10):1728
7. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to zinc and maintenance of normal skin (ID 293), DNA synthesis and cell division (ID 293), contribution to normal protein synthesis (ID 293, 4293), maintenance of normal serum testosterone concentrations (ID 301), “normal growth” (ID 303), reduction of tiredness and fatigue (ID 304), contribution to normal carbohydrate metabolism (ID 382), maintenance of normal hair (ID 412), maintenance of normal nails (ID 412) and contribution to normal macronutrient metabolism (ID 2890) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010;8(10):1819
8. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to iodine and thyroid function and production of thyroid hormones (ID 274), energy yielding metabolism (ID 274), maintenance of vision (ID 356), maintenance of hair (ID 370), maintenance of nails (ID 370), and maintenance of skin (ID 370) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1214
9. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to vitamin C and protection of DNA, proteins and lipids from oxidative damage (ID 129, 138, 143, 148), antioxidant function of lutein (ID 146), maintenance of vision (ID 141, 142), collagen formation (ID 130, 131, 136, 137, 149), function of the nervous system (ID 133), function of the immune system (ID 134), function of the immune system during and after extreme physical exercise (ID 144), non-haem iron absorption (ID 132, 147), energy-yielding metabolism (ID 135), and relief in case of irritation in the upper respiratory tract (ID 1714, 1715) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1226
10. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to vitamin C and reduction of tiredness and fatigue (ID 139, 2622), contribution to normal psychological functions (ID 140), regeneration of the reduced form of vitamin E (ID 202), contribution to normal energy yielding metabolism (ID 2334, 3196), maintenance of the normal function of the immune system (ID 4321) and protection of DNA, proteins and lipids from oxidative damage (ID 3331) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010; 8(10):1815
11. EFSA Panel on Dietetic Products, Nutrition and Allergies.  Scientific Opinion on the substantiation of health claims related to vitamin E and protection of DNA, proteins and lipids from oxidative damage (ID 160, 162, 1947), maintenance of the normal function of the immune system (ID 161, 163), maintenance of normal bone (ID 164), maintenance of normal teeth (ID 164), maintenance of normal hair (ID 164), maintenance of normal skin (ID 164), maintenance of normal nails (ID 164), maintenance of normal cardiac function (ID 166), maintenance of normal vision by protection of the lens of the eye (ID 167), contribution to normal cognitive function (ID 182, 183), regeneration of the reduced form of vitamin C (ID 203), maintenance of normal blood circulation (ID 216) and maintenance of normal a scalp (ID 2873) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010; 8(10):1816
12. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to copper and protection of DNA, proteins and lipids from oxidative damage (ID 263, 1726), function of the immune system (ID 264), maintenance of connective tissues (ID 265, 271, 1722), energy-yielding metabolism (ID 266), function of the nervous system (ID 267), maintenance of skin and hair pigmentation (ID 268, 1724), iron transport (ID 269, 270, 1727), cholesterol metabolism (ID 369), and glucose metabolism (ID 369) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1211
13. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to selenium and protection of DNA, proteins and lipids from oxidative damage (ID 277, 283, 286, 1289, 1290, 1291, 1293, 1751), function of the immune system (ID 278), thyroid function (ID 279, 282, 286, 1289, 1290, 1291, 1293), function of the heart and blood vessels (ID 280), prostate function (ID 284), cognitive function (ID 285) and spermatogenesis (ID 396) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2009; 7(9):1220
14. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to selenium and maintenance of normal hair (ID 281), maintenance of normal nails (ID 281), protection against heavy metals (ID 383), maintenance of normal joints (ID 409), maintenance of normal thyroid function (ID 410, 1292), protection of DNA, proteins and lipids from oxidative damage (ID 410, 1292), and maintenance of the normal function of the immune system (ID 1750) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2010; 8(10);1727
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