Signs of Vitamin D Deficiency You Should Not Ignore

The NIH Office of Dietary Supplements identifies fatigue, bone pain, muscle weakness, and mood changes as primary symptoms of vitamin D deficiency. These symptoms are often vague enough to be attributed to other causes, delaying diagnosis.

Frequent infections and slow wound healing may also indicate insufficient vitamin D, as it plays a critical role in immune function. Many people experience these symptoms for months or years before testing reveals the underlying deficiency.

The NIH identifies several groups at elevated risk: people with darker skin, older adults, those with limited sun exposure, and individuals with obesity. Melanin reduces the skin's ability to produce vitamin D from sunlight, increasing dietary requirements.

People living in northern latitudes receive insufficient UVB radiation during winter months to produce adequate vitamin D. Office workers and others who spend most daylight hours indoors face similar challenges regardless of geographic location.

A 25-hydroxyvitamin D blood test is the standard method for assessing vitamin D status. The NIH considers levels below 20 ng/mL deficient and 20-29 ng/mL insufficient. Many providers target 30-50 ng/mL as optimal.

Vitamin D3 supplements are the most effective form for raising blood levels. The NIH recommends 600-800 IU daily for most adults, though higher therapeutic doses may be needed under medical supervision to correct existing deficiency.