💊 Vitamins

Vitamin D: What It Means for Your Health

Vitamin D is a fat-soluble vitamin that your skin produces when exposed to sunlight. It plays a crucial role in calcium absorption, bone mineralization, immune regulation, and mood balance. The 25-hydroxy vitamin D test measures the storage form of vitamin D in your blood and is the most accurate way to determine your vitamin D status. Deficiency is extremely common worldwide, especially in northern latitudes and among people with limited sun exposure.

Full Name
25-Hydroxy Vitamin D (25-OH Vitamin D)
Normal Range
30–100 ng/mL
Also Known As
25-OH Vitamin D, Vitamin D3, 25-Hydroxy Vitamin D, Vit D

Reference Range

LowNormal: 30–100 ng/mLHigh

Reference ranges may vary between laboratories, age groups, and sexes. The values shown are general adult reference ranges. Always compare your results to the specific range provided by your testing laboratory.

What Is Vitamin D?

Vitamin D is a fat-soluble vitamin that your skin produces when exposed to sunlight. It plays a crucial role in calcium absorption, bone mineralization, immune regulation, and mood balance. The 25-hydroxy vitamin D test measures the storage form of vitamin D in your blood and is the most accurate way to determine your vitamin D status. Deficiency is extremely common worldwide, especially in northern latitudes and among people with limited sun exposure.

Commonly included in:

Vitamin D TestBone Health PanelWellness Panel

What Does High Vitamin D Mean?

Above 100 ng/mL

Very high vitamin D levels (above 100 ng/mL) can cause toxicity, leading to hypercalcemia (high blood calcium), nausea, vomiting, weakness, kidney stones, and kidney damage. Toxicity is almost always caused by excessive supplementation, not sun exposure or diet. Levels between 60-100 ng/mL are generally considered safe.

What Does Low Vitamin D Mean?

Below 30 ng/mL

Vitamin D deficiency (below 20 ng/mL) or insufficiency (20-29 ng/mL) is one of the most common nutritional deficiencies globally. It increases the risk of osteoporosis, fractures, muscle weakness, immune dysfunction, depression, and fatigue. Risk factors include limited sun exposure, darker skin pigmentation, obesity, malabsorption conditions, and advancing age.

Related Biomarkers in Vitamins

Vitamin B12
Essential vitamin for nerve function, DNA synthesis, and red blood cell formation.
Range: 200–900 pg/mL
Folate
B vitamin critical for cell division, DNA synthesis, and fetal development.
Range: 3–20 ng/mL
Vitamin A
Fat-soluble vitamin essential for vision, immune function, and skin health.
Range: 30–65 ug/dL

Track Your Vitamin D Over Time

Upload your blood test results to Hemoly and see how your Vitamin D levels change over time. Get trend analysis, educational insights, and a personal health timeline.

Download Hemoly for iOS

Medical Disclaimer

This information is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Reference ranges may vary between laboratories. Always consult a qualified healthcare professional for interpretation of your blood test results and before making any health decisions.