4beta-formylmethyl-4alpha-methyl-5alpha-cholesta-8,24-dien-3beta-ol + NADH + O2 => 4beta-carboxy-4alpha-methyl-5alpha-cholesta-8,24-dien-3beta-ol + NAD(+) + H2O
4beta-formylmethyl-4alpha-methyl-5alpha-cholesta-8,24-dien-3beta-ol + nadh + o2 => 4beta-carboxy-4alpha-methyl-5alpha-cholesta-8,24-dien-3beta-ol + nad(+) + h2o