Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics.
This week: Focus on Zinc
After iron, zinc is the second most abundant trace element in the human body, an important component in over 300 different enzyme systems and involved in many biological processes including immune function; wound healing, reproduction, taste, smell, blood clotting, and thyroid function.
- The recommended daily intake of zinc in adult men is 14mg/day and adult women 8mg/day. This can ordinarily be achieved by dietary intake of zinc. Foods which have high levels of zinc are meat, seafood, dairy products, nuts, legumes and whole grains.
- Zinc has been included as a component of barrier sunscreen for many years. Although they are effective, zinc-based sunscreens have largely been superseded by other products perceived as more cosmetically attractive but of equal efficacy.
- Several small clinical trials have shown an improvement in acne after the use of either oral or topical zinc products. The effects are thought to be mediated through anti-inflammatory action associated with inhibition of leukocyte chemotaxis.
- A Cochrane review found that the use of zinc lozenges decreased the duration but not the severity of the common cold symptoms in adults. The review also found a lower incidence rate of developing a cold, school absences and lower antibiotic prescription rates when comparing zinc group to the control.
- For treatment proven zinc deficiency the dose depends on the extent of deficiency, but a dose 150-300 mg (zinc sulphate) daily is often used.
- Adverse effects associated wth long-term use of zinc supplements include gastrointestinal adverse effects, copper deficiency,and anaemia.
Please consider these issues when preparing or interpreting RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to firstname.lastname@example.org.