Ask An Endo: What’s up with Vitamin D

Blog, Wellness

By: Dr. Richard Jackson, MD

Vitamin D is everywhere these days, and in more ways than one. It is literally everywhere, as our main source of vitamin D comes from exposure to the sun. We also get some vitamin D from the supplementation of milk and some cereals. Vitamin D is crucial for bone health in children and adults, and treating low levels of vitamin D with oral vitamin D supplements can prevent bone diseases such as rickets and osteomalacia in susceptible individuals.

Vitamin D is also everywhere in the health and wellness literature, as reports have linked low levels of vitamin D to increased risk for: type 2 diabetes, type 1 diabetes, heart disease, cancer, impaired immune function, and early mortality. Importantly, unlike bone disease, multiple studies have failed to show any change in risk or improvement in health when people were given supplemental vitamin D long-term.

This leads to the question of what is a normal vitamin D level? The best current answer is backed by the Institute of Medicine, and is 20 ng/ml or 50 nmol/L.  If you do have vitamin D levels below 20 ng/ml, there are a number of easy, inexpensive vitamin D preparations that can boost your levels back above 20 ng/ml.

It’s important to note that too much vitamin D can be toxic, and some studies showed that using vitamin D to boost blood levels to higher amounts caused an increase in falls in older adults.

Dr. Richard Jackson is an Endocrinologist who worked for more than 30 years with the Joslin Diabetes Center in Boston, MA.