If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Calcium is an important electrolyte in the body that plays a role in many functions. Having a calcium level that is too low (hypocalcemia) can cause numbness, tingling, muscle cramps, lethargy, abnormal heartbeat, and facial twitching.
Chronically low calcium can lead to osteoporosis. Having a calcium level that is too high (hypercalcemia) can cause kidney stones, bone pain, abdominal pain, confusion, and abnormal heartbeat.
Calcium levels are regulated by the parathyroid gland. Calcium levels can be raised with diet and supplements; calcium levels can be lowered with a variety of medications. You can read more about calcium here.
What we mean by normal
In medicine, using the term “normal” can sometimes be off-putting. Saying something is normal implies that everything else is abnormal.
Additionally, saying something is normal may not be accurate, since something that is normal for you may not be normal for somebody else. Therefore, instead of saying certain values are normal, alternative terminology may be to say that these values are healthy or within the reference range.
Additionally, some values have well-defined cutoffs, while others do not. For example, when looking at hemoglobin A1c levels, a value of 6.5 or greater is always diagnostic of diabetes. On the other hand, when looking at testosterone levels, some use cutoffs of 270–1,070 ng/dL while others use cutoffs of 300–1,000 ng/dL.
The information below represents values that are commonly used as cutoffs. However, depending on the specific source you’re looking at or the laboratory you go to, their values may be a little different.
Dr. Tzvi Doron is Board Certified in Family Medicine by the American Board of Family Medicine and is Ro's Chief Clinical Officer.