What is a healthy vitamin D level?

A vitamin D level between 20 and 50 nanograms per milliliter is healthy, according to the National Institutes of Health. Vitamin D helps the body absorb calcium, which is important for bone formation.

Tests to measure for vitamin D check for the amount of 25(OH)D, also known as calcidiol, in the blood. Scientists consider this the best measurement because it reflects both the vitamin D produced by the body as well as any that is present from food or supplements.

A deficiency of vitamin D potentially leads to poor bone growth, rickets in young children or osteomalacia in adults. It is not known if high levels are dangerous, but there is some evidence that very high vitamin D concentrations sometimes have adverse health effects, according to the National Institutes of Health.