To Your Health
April, 2010 (Vol. 04, Issue 04) |
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Avoiding overexposure to sunlight (and other known sources of free radicals), wearing protective clothing and using antioxidant-containing sunblock creams and lotions are prudent strategies to minimize risk of premature skin aging and skin cancer.
Recent studies have indicated that the use of antioxidant supplements can further help to protect the skin from free-radical damage and age-related changes linked to premature wrinkling and cancerous mutations. A double-blind, placebo-controlled study in human subjects demonstrated that subjects taking vitamin C (2,000 mg per day) and vitamin E (1,000 IU) supplements had significantly less free-radical damage to their skin after UV-light exposure than did subjects not given the antioxidant supplement regime. They also showed significantly less sunburn reaction.
Further, it has been shown that free radicals (especially sun exposure) deplete the skin of its antioxidant defenses quite rapidly, further increasing the requirement for nutritional antioxidants to replenish these important cellular antioxidants. Other laboratory studies reveal that selenium, zinc and N-acetyl-cysteine supplementation can also defend skin cells against free radicals from UV light. Intensive investigation in this area of study strongly suggests that the daily supplementation of vitamins A, C, E, beta-carotene, selenium and zinc, at levels above those typically consumed from food alone, provides the skin with additional and possibly essential antioxidant defenses to help slow skin aging; and lends important support to other skin-cancer prevention initiatives.
Vitamin A
All epithelial cells (including skin cells) require vitamin A (which the body can make from beta-carotene if necessary) to achieve their full, mature development, and for the production of mucus and other secretions that keep these tissues moist and resistant to infection. In the absence of adequate vitamin A, epithelial tissue does not produce these secretions, but instead becomes covered with keratin, which is a dry, water-insoluble protein that transforms soft, moist skin into skin that is hard and dry, or keratinised. Vitamin A deficiency, in fact, produces a precancerous type of condition known as metaplasia in various epithelial cells, whereby affected cells appear grossly enlarged and highly irregular and abnormal upon microscopic examination.
At the same time, skin cells are particularly responsive to vitamin A supplementation for a number of conditions, and a topical form of vitamin A has been used with success in the treatment of acne vulgaris. Vitamin A supplementation has been shown to be beneficial in wound healing, as it stimulates the synthesis of collagen. As such, some physicians recommend short-term supplementation with 25,000-50,000 IU of vitamin A prior to and following surgery and dermatological procedures to enhance healing and to help ensure more complete healing of the skin and connective tissues.
The National Health and Nutrition Examination Survey II demonstrated that vitamin A intake is of concern across the U.S. population, with 50 percent of adult Americans consuming less than the RDA. For this reason, it is advisable to consider a daily supplement containing 2,000-3,000 IU of vitamin A and 10,000-15,000 IU of beta-carotene to help support skin health and appearance. Certain conditions may require higher doses for short periods of time, but long-term supplementation with higher doses of preformed vitamin A (beta-carotene is nontoxic by comparison) can result in vitamin A toxicity, which among other serious outcomes can cause severe skin dryness and peeling.
B Vitamins
Virtually all B vitamins are required at sufficient doses to ensure healthy development of skin cells. In fact, deficiencies in many B vitamins directly result in various types of skin conditions, skin diseases and alterations in the normal appearance of the skin. Even marginal deficiencies of B vitamins can produce chronic skin lesions that are not treatable with topical agents alone.
For instance, nasolabial seborrhoea (characterized by fissuring and redness at the corners of the eyes and mouth, among other symptoms) is known to result form marginal deficiencies in niacin, vitamin B6 or vitamin B2. Hyperpigmentation (color of skin changes first to red, then to brown) can result from niacin deficiency. Angular stomatitis (redness, cracking and flaking at the corners of the mouth) can result form a marginal deficiency of vitamin B2, vitamin B6, niacin or iron. Supplementation with appropriate doses of specific B vitamins can reverse these conditions if a B-vitamin deficiency is a contributing cause of the problem, as is often the case.
