Possible Clues:

• Cobalt in the human body, e.g
• Car competition with component promoted on the box for foodie types
• Mineral required only in minute amounts
• Car competition with component promoted on the box for foody types
• Copper, perhaps, to follow soldiers in TV western
• Iron, say, liquid metal centre containing energy
• Something in very small quantities in the body (2 words)
• Constituent present in only small amounts
• Chemical present in small quantities
• Animals need hardly any of this wine when drinking brawl wheels about