Final answer:
The claim about Go-well Vitamins is unsupported due to reliance on a personal testimonial rather than objective scientific evidence or clinical research.
Step-by-step explanation:
The claim about Go-well Vitamins is unsupported by sufficient evidence because the passage centers on a personal testimonial and lacks any reference to scientific research or studies providing objective data. Personal anecdotes can be subjective and may not accurately represent the effectiveness of a product for the wider population. Additionally, the claims about the vitamins making skin "shiny and clear" could be influenced by placebo effects or other factors unrelated to the vitamins themselves. Proper scientific research, clinical trials, or statistically significant data would be required to support the claim that the vitamins produce the advertised effects.