Protein shakes are convenient, but they're highly processed and lack essential nutrients. Dietitians share 13 healthy, ...

Vitamin D is a fat-soluble vitamin critical for bone growth and cell development. Rainbow trout, salmon, sardines, tuna, mackerel, and herring are good sources.

Vitamins C, A, and B are supplements that can be taken with iron to improve energy and reduce tiredness and fatigue.

While they may be beneficial on their own, taking these supplements together could hinder absorption or be outright unsafe.