Vitamin D Calculator – Check Levels & Daily Supplement Dose

Normal vitamin D blood levels are generally considered 30-100 ng/mL (75-250 nmol/L). Below 20 ng/mL is considered deficient, 20-29 ng/mL is insufficient. Your healthcare provider may have different reference ranges.

Common symptoms include fatigue, muscle weakness, bone pain, mood changes, and frequent infections. However, many people with deficiency have no symptoms, which is why testing is important.

Most people need 10-30 minutes of midday sunlight several times per week. However, factors like latitude, season, skin tone, and age affect vitamin D production. Sun protection and supplementation are often necessary.

Yes, excess vitamin D can cause toxicity, though this is rare from sun exposure or food. Excessive supplementation (above 4,000 IU daily consistently) can lead to elevated calcium levels and health problems. Follow your healthcare provider's recommendations.

Good dietary sources include fatty fish (salmon, mackerel), egg yolks, mushrooms exposed to sunlight, and fortified dairy or plant-based milks. Most people cannot get adequate vitamin D from diet alone.

Many people benefit from supplementation, especially those with limited sun exposure, dark skin in northern climates, or diagnosed deficiency. Consult your healthcare provider about whether supplementation is appropriate for you.