Your cardiovascular system is an important and fragile group of structures that pumps nutrient - and oxygen-rich blood throughout your body.

Those are also symptoms of a deficiency of B-12, a key nutrient needed to make red blood cells and DNA and keep the nervous system working right.

There are some nutrient sources - such as selenomethionine, a widely used form of selenium, boron for bone health and chromium yeast for regulating blood sugar - that aren't on the list.