Eight different isomeric forms of vitamin E (4 tocopherols and 4 tocotrienols) have been
found in nature. Tocotrienols (α, β, γ and δ) are identical in structure to tocopherols except
for the degree of saturation in their side chain. However, α-tocopherol is considered to be
the most active form of vitamin E in humans. It has been found that the concentrations of
vitamin E isomers in human feces are higher than in plasma – possibly due to its limited
absorption from the diet, suggesting that it could play a protective role against RONS
produced in the GI tract (Halliwell...
Internal iron exchange.
Normally about 80% of iron passing through the plasma transferrin pool is recycled from broken-down red cells. Absorption of about 1 mg/d is required from the diet in men, 1.4 mg/d in women to maintain homeostasis.
As long as transferrin saturation is maintained between 20–60% and erythropoiesis is not increased, iron stores are not required. However, in the event of blood loss, dietary iron deficiency, or inadequate iron absorption, up to 40 mg/d of iron can be mobilized from stores. RE, reticuloendothelial.