Iodine in biology
The U.S. Food and Nutrition Board and Institute of Medicine recommended daily allowance of iodine ranges from 150 micrograms per day for adult humans to 290 micrograms per day for lactating mothers. However, the thyroid gland needs no more than 70 micrograms per day to synthesize the requisite daily amounts of T4 and T3. The higher recommended daily allowance levels of iodine seem necessary for optimal function of a number of other body systems, including lactating breasts, gastric mucosa, salivary glands, oral mucosa, arterial walls, thymus, epidermis, choroid plexus and cerebrospinal fluid, among others.
Tincture of iodine
Iodine solution is used to sanitize the surface of fruit and vegetables for bacteria and virus. The common concentration for sanitization is 25 ppm idophor for 1 minute. However, the effectiveness depends on whether the solution penetrates into rifts, and whether dirt is effectively removed at first. But, oocytes of protozoan parasites will not be killed, and it is also doubtful that bacterial spores are killed. Iodine solutions should not be considered able to sanitize or disinfect salad, fruit or vegetables that are contaminated by feces. Thus, it should not be considered safe to eat raw fruit, salads and vegetables which are sanitized with iodine, if they could be contaminated by feces.