An adequate supply of nutrients is essential for health, performance and well-being. This also includes iodine, iron, folic acid and vitamin B12. For women of childbearing potential, pregnant and lactating women, the elderly, and people who eat only leafy vegetables rich in folic acid irregularly, iodine-containing foods (eg fish), and iron-rich animal foods and B12 (eg meat), is an adequate supply of these nutrients is particularly important.