Multivitamins
Three investigations evaluated multivitamin supplementation in CiO(Weijl et al., 2004, Villani et al., 2016, Scasso et al., 2017). A multivitamin beverage that contained vitamin C, vitamin E, and selenium was used as CiO profilaxis in a RCT. At 12 months they did not find any difference between the occurrence of nephrotoxicity and ototoxicity induced by cisplatin. However, patients with the highest micronutrient antioxidant values at the start of chemotherapy had significantly less loss of high-tone hearing than patients with low values (conduction threshold at 8.0 kHz 2.8 vs. 14.4 dB; p=0.028)(Weijl et al., 2004). Another RCT compared the protective effect of vitamin E supplementation for 3 months against placebo in CiO. At 1 month the control group had significant hearing loss at both 2000 Hz (right ear: p=0.05; left ear: p=0.04) and 8000 HZ (right ear: p=0.04; left ear: p=0.03) when compared with baseline values. Audiograms did not show significant changes in the active group at 2000, 4000, and 8000 Hz. Evoked brainstem responses remained unchanged in both groups. The planned follow-up evaluations weren’t completed because of a 37% patient drop-out (Villani et al., 2016). Ultimately a case-control study tested if dietary supplementation with coenzyme Q10 plus multivitamins could preemptively reduce reactive oxygen species and consequently CiO. They found that patients on dietary supplementation, 7 days before and 21 days after chemotherapy, had a significantly lower amount of reactive oxygen metabolite derivatives (P < 0.05) and a stable range of blood antioxidants (P < 0.05) compared to the control group. Moreover, the intervention group showed lesser augmentation on the hearing threshold level at 8000 Hz frequency 6.9 ± 11.8 dB compared to the control group 20.0 ± 16.2 dB (P < 0.05). Similarly, tinnitus incidence was higher in the control group (62.5% vs 11.1% P < 0.05). In this study, 69% of patients received concomitant head radiation (dose not specified)(Scasso et al., 2017). None of the studies reported adverse effects due to vitamin supplementation, only the patient´s dislikeness for the taste of the supplementation product.