What it does
Helps calcium absorption and bone mineralization.
Possible deficiency symptoms
Deficiency can weaken bones; severe deficiency can cause bone pain or muscle weakness. Many people have no obvious symptoms.
Food sources
Fatty fish; egg yolks; fortified milk or plant drinks; some UV-exposed mushrooms. Sun exposure is not a food source.
Supplement forms
D2 (ergocalciferol) and D3 (cholecalciferol). The usual blood-status marker is 25-hydroxyvitamin D.
Before taking a supplement
Excess supplementation can raise calcium and harm kidneys. Lab interpretation and dose depend on your circumstances.
Questions for your visit
Could my diet, medicines, absorption or another condition explain my concern? What evidence would support treatment, and how would we check whether it helps?
Names you may see
Vitamin D
Sources & perspective
This is an editorial adaptation of the Purser Wellness nutrient reference app. Purser teaching connections are labeled separately from clinical interpretation. Private cases and individual treatment protocols are not reproduced.
Use the public resources below for additional context.
NIH Office of Dietary Supplements: Vitamin D
