Precautions and contraindications.
Patients with a shellfish allergy should use extreme caution in taking chitosan supplements, as many are de- rived from shellfish products. Chitosan products may be contaminated with heavy metals, such as lead, mercury, iron, and copper; therefore, chitosan should be avoided in children, pregnant patients, and nursing mothers.
Interactions.
No drug interactions involving chitosan have been reported, but caution may be warranted when administering chitosan concurrently with highly lipophilic drugs.8 There are theo- retical concerns about chitosan decreas- ing the absorption of fat-soluble vita- mins, although clinical trials have not shown this to be the case. Conclusion. The limited information currently available indicates that chito- san is not effective in weight management without concurrent lifestyle and dietary modifications. Longerterm trials are necessary to assess the utility of this agent in maintaining weight loss. Simi- larly, chitosan’s impact on serum lipid levels, if any, needs to be confirmed by large and rigorous clinical trials. The studies performed thus far suggest that cholesterol benefits are linked more to subjects’ weight loss than to chitosan.