Possible Clues:

• *Niacin and riboflavin
• Thiamine and riboflavin
• Thiamine and riboflavin, e.g
• Niacin and riboflavin
• Niacin and riboflavin, for two
• Niacin and thiamine, for two
• Biotin, thiamine et al
• Thiamine and niacin e.g.