Vitamin B6 is a water-soluble vitamin that helps your body form red blood cells and maintain brain function. This vitamin also assists with the functioning of proteins and enzymes in your body. Large amounts of vitamin B6 are lost during most forms of cooking and processing. Loss of vitamin B6 from canning of vegetables can be up to 70%, although losses on standard home cooking will be lower (20–60%).
Cut your veg into large pieces as you’re less likely to sever cell walls or lose nutrients to heat, light or cooking water.