What is a common deficiency you see on a regular basis?

Calcium is a common deficiency and is crucial for maintaining bone strength, important in new bone growth, helps maintain heart rhythm, and muscle function. People who are at highest risk for calcium deficiency are postmenopausal women. Since dairy products are a common source for calcium, those who are lactose intolerant, as well as vegans, would also be at risk. Calcium supplements are available over-the-counter and best when taken with food and are better absorbed when consuming 500 mg or less at a time.