The ATP yield for every oxidation cycle is theoretically a maximum yield of 17, as NADH produces 3 ATP, FADH 2 produces 2 and a full rotation of the citric acid cycle produces 12. [ citation needed ] In practice it's closer to 14 ATP for a full oxidation cycle as in practice the theoretical yield isn't attained - it's generally closer to ATP per NADH molecule produced, for each FADH 2 Molecule produced and this equates to 10 per cycle of the TCA [ citation needed ] (according to the P/O ratio ), broken down as follows:
A low dietary intake of carotenoids such as beta-carotene is not known to directly cause any diseases or health conditions, at least in the short term. However, long-term inadequate intake of carotenoids is associated with chronic disease, including heart disease and various cancers. One important mechanism for this carotenoid-disease relationship appears to be free radicals. Research indicates that diets low in beta-carotene and carotenoids can increase the body’s susceptibility to damage from free radicals. As a result, over the long term, beta-carotene deficient diets may increase tissue damage from free radical activity, and increase risk of chronic diseases like heart disease and cancers. Diets low in beta carotene may reduce the effectiveness of the immune system and lead to an increased risk of cancer and heart disease. Old persons with type 2 diabetes have shown a significant age-related decline in blood levels of carotenoids, irrespective of their dietary intake. Symptoms of a beta-carotene deficiency mimic those of a vitamin A deficiency: dry skin, night blindness, susceptibility to infection. Such deficiencies are seldom seen, however, even in people who don't eat fruits or vegetables or take supplements, because so many other foods supply the nutrient.