Keyword: - Ryoko Nail Defense Official Website: https://www.facebook.com/RyokoNailDefense/ But what goes wrong? Brittle nails often stem from a multifactorial assault. Dehydration from frequent handwashing or dry climates strips moisture, leading to splitting. Nutritional gaps, like low biotin (vitamin B7) levels, impair keratin production, causing ridges and fragility. Visit ... https://www.facebook.com/RyokoNailDefense/