Calcium

Perhaps the last piece of nail improbability is the belief that applying calcium to your nails will make them strong. Calcium, along with lots of other minerals and vitamins, shows up in many nail-care products owing to the assumption that you can feed the nail from the outside in. You can’t feed the nail directly, though even if you could, calcium and other minerals are unlikely ingredients for this purpose. Calcium and minerals may help build strong bones (bones are primarily calcium), but that is unrelated to the content of nails. The notion of having nails as strong as bone does make calcium sound appealing. However, even by itself calcium can’t build bone; the body needs other vitamins and minerals to use the calcium. Moreover, there is virtually no calcium in nails; they’re made of keratin and that’s about it.