Because the body converts all dietary sources of vitamin A into retinol, 1 mcg of physiologically available retinol is equivalent to the following amounts from dietary sources: 1 mcg of retinol, 12 mcg of beta-carotene, and 24 mcg of alpha-carotene or beta-cryptoxanthin.
The body needs more omega-3 than omega-6 to reduce the risk of heart disease and inflammation. Since olive oil is higher in omega-3 than other oils, sardines in olive oil contain more omega-3 than sardines in water; however, the sardines in water are still the better option with lower amounts of cholesterol and fat.
The oily fish contains good amounts of vitamins B12 and selenium, which have been found helpful in the treatment of cancer. Immunity. Mackerel fortifies the immune system. It supports the functions of organs that have been weakened by sickness.