Vitamin D
Vitamin D helps your body absorb calcium (bone health) and plays a role in immune function. Your body makes it from sun exposure on skin, and it's also in some foods and supplements.
Your reading
This app uses 30–60 ng/mL as the target range — the stricter of two common clinical thresholds (the Endocrine Society uses 30 as the cutoff for sufficiency; the Institute of Medicine uses 20). If your result sits between 20 and 30, some clinicians would call that sufficient and others wouldn't — it's a genuinely contested threshold, not a settled number.
What may help
- —10–30 minutes of midday sun on bare skin, several times a week (varies a lot by latitude, season, and skin tone)
- —Fatty fish (salmon, mackerel, sardines), egg yolks, and fortified foods (milk, cereal)
- —A vitamin D3 supplement — this is one of the few vitamins where supplementation is genuinely common and well-studied, especially at higher latitudes or in winter
When to talk to a doctor
If your level is well below 20 ng/mL, or you have symptoms like bone pain or muscle weakness — a doctor can advise on dosing, since too much vitamin D (from supplements, not sun) can cause its own problems.
Source: MedlinePlus (NIH). Reference ranges are standard adult intervals — your own lab may report a different range for your age, sex, or method. This isn't medical advice; always go by the range on your actual results and talk to a clinician about anything that concerns you.