Vitamin D deficiency can be linked with bone pain in adults caused by osteomalacia. Possible symptoms are not specific, so they cannot tell you whether your vitamin D is low on their own.[1]
This is evidence-only information. It does not diagnose vitamin D deficiency, recommend a treatment dose or replace individual medical advice.
When to seek urgent help
Use urgent NHS care for emergency symptoms
Call 999 for a life-threatening emergency, collapse, severe breathing difficulty or severe chest pain. For urgent symptoms that do not need 999, use NHS 111. A routine vitamin D test is not a substitute for urgent assessment.
Who may benefit from a clinical discussion?
NICE CKS advises considering a serum 25-hydroxyvitamin D test when someone has musculoskeletal symptoms that may be attributable to deficiency, suspected bone disease that may benefit from treatment, or specific bone-treatment contexts. It advises not routinely testing people who are asymptomatic.[2]
Symptoms and bone health
Bone pain, proximal muscle weakness or a clinical concern about osteomalacia can be reasons for a clinician to consider testing.
Sunlight exposure
People who rarely go outdoors, cover most skin outdoors or have dark skin may be at higher risk of not making enough vitamin D from sunlight.
Diet and supplements
Food and supplements contribute to vitamin D intake. Tell the clinician about any supplement already being taken.
Other explanations
Fatigue, aches or low mood may have many causes. A test should be part of an assessment, not a shortcut to one explanation.
Testing and result limits
The usual blood test is serum 25-hydroxyvitamin D. NICE CKS describes it as the best clinical indicator of vitamin D status; it reflects recent skin synthesis and dietary sources. It is different from the active vitamin D metabolite, which is not a useful general indicator of vitamin D status.[2]
Laboratory results need interpretation in context. This page does not provide a self-diagnosis table, target value, report turnaround promise or treatment dose. The clinic confirms suitability, preparation, reporting and follow-up for an individual route at booking.
Supplements: prevention and safety
The NHS says that everyone should consider a daily vitamin D supplement during autumn and winter. People at higher risk of not getting enough vitamin D may be advised to take a supplement throughout the year. The NHS gives general population advice of 10 micrograms per day for people aged 1 and over, including pregnant and breastfeeding women.[1]
General prevention advice is not the same as a treatment plan for confirmed deficiency. Do not exceed NHS upper-limit advice without clinical guidance. Some health conditions and medicines affect what is suitable, and excessive supplementation can cause hypercalcaemia.[1]
Frequently asked questions
Should everyone have a vitamin D blood test?
No. NICE CKS advises against routine testing in people without symptoms. The clinical reason for testing matters.
What does the usual test measure?
Serum 25-hydroxyvitamin D, often written as 25(OH)D, is the usual measure of vitamin D status in an appropriate clinical assessment.
Can fatigue prove vitamin D deficiency?
No. Fatigue and low mood have many possible causes. A result should be interpreted alongside symptoms, risk factors and other relevant information.
Can vitamin D supplements be harmful?
Yes. The NHS warns that too much vitamin D over time can cause high calcium levels and harm the bones, kidneys and heart. Follow individual clinical advice where this differs from general prevention advice.
Related routes and information
References
Sources checked 30 August 2026. This evidence-only page does not replace individual assessment, diagnosis or urgent medical care.