Understanding Your Vitamin D

The vitamin D test measures the level of vitamin D in your blood. Vitamin D supports strong bones, immune function, and overall energy, and deficiency is very common.

What It Measures

The test checks a form of vitamin D called 25-hydroxyvitamin D, the best marker of your overall vitamin D stores. Your body makes vitamin D from sunlight and absorbs some from food and supplements.

What Your Results Can Mean

Result What It Means
LowDeficiency or Insufficiency Common, especially in winter or with limited sun exposure. It can contribute to fatigue, bone and muscle aches, and weaker bones over time.
NormalAdequate Stores Your vitamin D level supports healthy bones and immune function.
Very HighExcess Usually from taking too much supplement. Rarely, it can raise calcium to unhealthy levels.

What’s Most Important to Know

Low vitamin D is easy to correct with sunlight, diet, and supplements. If yours is low, Dr. Mui will recommend a dose and, when needed, recheck the level later.

Vitamin D is one piece of bone and overall health. We consider it alongside your calcium, symptoms, and risk factors.

This page is for general education and does not replace a conversation with your doctor about your specific results. Want to review your results? Book a visit and we’ll go through them together.