Nutritional support for wound healing

Alternative Medicine Review, Nov, 2003 by Douglas J. MacKay, Alan L. Miller

Vitamins and Minerals Essential to Wound Healing Vitamin A

Vitamin A is required for epithelial and bone tissue development, cellular differentiation, and immune system function. Substantial evidence supports the use of vitamin A as a perioperative nutritional supplement. (5) In addition to facilitating normal physiological wound repair, Ehrlich and Hunt have shown vitamin A reverses the corticosteroid-induced inhibition of cutaneous and fascial wound healing. (6-8) Vitamin A has also corrected non-steroid induced, post-operative immune depression (9) and improved survival in surgically-induced abdominal sepsis. (10) Levenson et al suggest vitamin A benefits the wound by enhancing the early inflammatory phase, including increasing the number of monocytes and macrophages at the wound site, modulating collagenase activity, supporting epithelial cell differentiation, and improving localization and stimulation of the immune response. (10,11)

Animal studies show vitamin A may increase both collagen cross-linkage and wound-breaking strength. Greenwald et al inflicted surgical flexor profundus damage and immediate repair on adult chickens. They found chickens that ate a diet supplemented with vitamin A (150,000 IU/kg chicken chow) demonstrated wound-breaking strength more than double that of controls fed standard chicken chow. (12) In addition, rats with dorsal skin incisions and concurrent comminuted femoral fractures exhibited delayed cutaneous healing. Supplemental vitamin A enhanced wound healing in these animals, demonstrated by increased breaking strength of the dorsal skin incisions in rats fed supplemental vitamin A compared to the non-supplemented group. The authors believe the improved wound healing is a result of an increased rate of collagen cross-linkage. (13)

Levenson and Demetrio recommend vitamin A supplementation of 25,000 IU daily before and after elective surgery. (14) Research supports perioperative vitamin A supplementation in patients known to be immune depleted or steroid treated. Surgical patients with sepsis and those with fractures, tendon damage, or vitamin A deficiency may also benefit from perioperative vitamin A supplementation. Additional research is necessary to establish the effectiveness of universal perioperative vitamin A supplementation in healthy individuals.

Concern among some practitioners regarding the potential toxicity of higher doses of vitamin A has led to uneasiness about using it perioperatively. The vast majority of toxicity cases have occurred at daily vitamin A dosages of 50,000-100,000 IU in adults over a period of weeks to years. (15) Short-term supplementation of 25,000 IU daily appears to be safe for most nonpregnant adults. Caution must be exercised in supplementing vitamin A in patients for whom the anti-inflammatory effect of steroids is essential, such as in rheumatoid arthritis or organ transplants. as well as in pregnant women and women of childbearing age. (5)

Vitamin C

Ascorbic acid is an essential cofactor for the synthesis of collagen, proteoglycans, and other organic components of the intracellular matrix of tissues such as bones, skin, capillary walls, and other connective tissues. Ascorbic acid deficiency causes abnormal collagen fibers and alterations of the intracellular matrix that manifests as cutaneous lesions, poor adhesion of endothelium cells, and decreased tensile strength of fibrous tissue. (16) Clinical manifestations of ascorbic acid deficiency include bleeding gums, poor immunity, easy bruising and bleeding, and slow healing of wounds and fractures. (17) Ascorbic acid is necessary for the hydroxylation of proline and lysine residues in procollagen, which is necessary for its release and subsequent conversion to collagen. Hydroxyproline also stabilizes the collagen triple-helix structure. (18) In addition to collagen production, ascorbic acid enhances neutrophil function, (19) increases angiogenesis, (20) and functions as a powerful antioxidant. (21)