Pressure Injuries

Vitamin C and Zinc for Healing Pressure Injuries

April 19, 2018   /




When a patient develops a pressure injury, many facilities implement protocols that include supplementation with vitamin C and/or zinc to enhance wound healing. Is this practice safe? Is it effective? Should dietetic practitioners recommend these nutrients for patients with pressure injuries?

Both vitamin C and zinc play a number of essential roles in the body, including involvement in collagen synthesis. Both nutrients are fairly safe at large doses.


Nutrition Management of Pressure Injuries Q&A
Risk Factors for Pressure Injuries

Vitamin C

The tolerable upper intake level for vitamin C in adults is 2000 milligrams (mg)/day. Toxicity may result in kidney stones, severe diarrhea, nausea, and gastritis. Occasionally, flushing, faintness, dizziness, and fatigue are noted with excessive vitamin C intake. Large doses may cause hemolysis (red blood cell destruction) in patients with glucose-6-phosphate dehydrogenase deficiency. People with conditions aggravated by acid loading, such as cirrhosis, gout, renal tubular acidosis, or paroxysmal nocturnal hemoglobinuria, should avoid high doses of vitamin C.

Routine supplementation with vitamin C probably will not hurt a patient, but it is unlikely that it will accelerate wound healing in those who are not deficient. Research indicates that mega doses of Vitamin C do not promote healing. A multivitamin supplement is recommended if a deficiency is confirmed or suspected.


Zinc has seen use since ancient times for wound healing, although clinical evidence to support its use is limited. As established by the Recommended Dietary Allowance (RDA), the tolerable upper intake level for zinc is 40 mg/day. Higher doses may cause vomiting, diarrhea, headaches, and a metallic taste in the mouth. Large doses of zinc may affect absorption of calcium and copper, and may interfere with many common medications, including hormone replacement therapy, antibiotics, and nonsteroidal anti-inflammatory drugs.

No evidence exists to support the routine use of mega does of elemental zinc to promote healing of pressure injuries but a multi-vitamin/mineral supplement is recommended if a deficiency is confirmed or suspected. Mega doses of elemental zinc can have consequences related to interactions with medications and nutrient absorption.

Sources of Vitamin C and Zinc

Vitamin C and zinc are widely available in foods, multivitamins, tube feeding formulas, and in liquid oral high calorie, high protein supplements. It is likely that patients who are eating at least fairly well and/or receiving other forms of oral nutritional supplements are obtaining the RDA for both vitamin C and zinc.

Foods that are high in vitamin C include citrus and other fruits, green vegetables, such as broccoli, kohlrabi, spinach, and collard greens, red and green bell peppers, tomatoes and tomato juices, and tropical fruits such as guava, papaya, and mango. Good sources of zinc in the diet include eggs, liver, meat, milk, seafood, tofu, wheat germ, and whole-grain foods.

Implications for dietetics practitioners

Therapeutic doses of vitamin C and zinc do not appear to improve wound healing unless a patient is deficient in those nutrients. Routine supplementation with these nutrients may not enhance wound healing. However, it is necessary to assess each patient individually because individuals who are deficient may benefit from a multivitamin /mineral supplement.

Registered dietitians (RDs) and registered dietitian nutritionists (RDNs) should include assessment of vitamin C and zinc status as part of routine nutrition assessment for pressure injury patients. This assessment should include a patient intake of foods containing vitamin C and zinc, clinical signs of vitamin C or zinc deficiency, side effects of mega doses, and interference of the nutrients with other prescribed medications. In some cases, a multivitamin/mineral supplement may prove beneficial, especially if a patient is not eating well.

Health care facilities should review their existing protocols for routine supplementation with vitamin C and zinc for patients with pressure injuries. RDs and RDNs can play a critical role in establishing protocols for supplementation and assessment of residents for nutrient deficiencies.

References and recommended readings

  1. Dorner, B. The Complete Guide to Nutrition Care for Pressure Ulcers. Naples, Fl. Becky Dorner & Associates, Inc. 2015.
  2. National Pressure Injury Advisory Panel, European Pressure Injury Advisory Panel, and Pan Pacific Pressure Injury Alliance. Prevention and Treatment of Pressure Ulcers: Clinical Practice Guideline. Emily Hauser (Ed). Cambridge Media: Perth, Australia, 2014.
  3. Vitamin C: Fact sheet for health professionals. National Institutes of Health Office of Dietary Supplements. Accessed October 18, 2017.
  4. Zinc: Fact sheet for health professionals. National Institutes of Health Office of Dietary Supplements. Accessed October 18, 2017.


Orginally Published: January 19, 2015

Reviwed and Updated: October 30, 2017