Several therapeutic approaches have been used in alkaptonuric patients. The protein origin of homogentisic acid was the base for therapeutic attempts with protein reduction in a diet. In the majority of patients, a decrease of homogentisuria was observed; however, regression of joint symptoms occurred only in rare cases. In order to reduce formation of ochronotic pigment and subsequently to reduce the risk of ochronosis with its harmful consequences especially in musculoskeletal system, some but not all authors reported positive effect is attributed to vitamin C. There are contradictory opinions on effectiveness of vitamin C and diet with protein reduction or their combination. While some authors present improvement of clinical syndromes (Morava et al. 2003; Turgay et al. 2009), other authors did not observe any improvement (Phornphutkul et al. 2002; Suwannarat et al. 2005). High doses of vitamin C decrease excretion of benzoquinone acetic acid, but not of homogentisic acid itself.