The elements and electrolytes in plankton are almost tailor-made for the human body. It's no coincidence that the composition of human plasma is similar to that of seawater. Over reliance on land-based food sources often leads to deficiencies in micronutrients and trace elements.
Our bodies need these elements to perform as nature intended. Left to its own devices, the human body has a marvelous system called homeostasis which keeps all systems in balance. Take away some critical component and the body experiences malfunctions that cause suboptimal performance. Too many malfunctions cause disease.