Adverse Outcomes of Vitamin Use
Like any intervention, the potential for adverse outcomes cannot be overlooked. AREDS reported an increased risk for genitourinary hospitalization (urinary tract infections, prostatic hyperplasia, and stress incontinence) in patients taking zinc; however, this was only a trend. Vitamin E may not be advisable for patients with bleeding problems or who are on anticoagulation. There have been findings of an increased risk of intracerebral and subarachnoid hemorrhage during treatment with carotene and alpha-tocopherol. Other evidence has shown that large amounts of vitamin A may lead to osteoporosis and hip fractures. More importantly, in light of strong evidence showing that beta-carotene may be harmful in smokers, most ophthalmologists now recommend high doses of vitamins E and C and zinc without beta-carotene to smokers or ex-smokers. However, we still cannot say with certainty that this combination without beta-carotene is as effective as the combination given in AREDS.