--- title: "Vitamin D deficiency: Symptoms & Treatment | HealthAnswers" description: "A plain-English guide to vitamin D deficiency — symptoms, who is at risk, testing and treatment in the UK." url: https://healthanswers.co.uk/conditions/vitamin-d-deficiency/ robots: noindex --- # Vitamin D deficiency: Symptoms & Treatment | HealthAnswers Health A–Z A plain-English guide to vitamin D deficiency — symptoms, who is at risk, testing and treatment in the UK. Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 3 July 2026 ## Quick answer What is vitamin d deficiency? Vitamin D deficiency means low levels of the vitamin that helps bones, muscles and immune function. In the UK, many people are low — especially in winter — because sunlight is the main source. Symptoms include tiredness, bone pain and muscle weakness. Supplements are recommended for most UK adults in autumn and winter. ## Who is this page for? This page is for people in the UK who want a plain-English overview of Vitamin D deficiency, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally. ## Who should skip this page? Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland. On this page 9 sections ## Key facts about vitamin d deficiency - Vitamin D is made in the skin from sunlight — hard to get enough from food alone in the UK. - NHS advises all adults consider 10 micrograms (400 IU) daily in autumn and winter. - Deficiency can cause bone pain, muscle weakness and tiredness. - Severe long-term deficiency causes rickets in children and osteomalacia in adults. - People with dark skin, who cover their skin, or who stay indoors are at higher risk. ## Why vitamin D matters in the UK Vitamin D helps the body absorb calcium and phosphate — essential for **healthy bones, teeth and muscles**. It also plays a role in immune function. In the UK, sunlight between **April and September** is the main source — the body makes vitamin D in skin exposed to UVB rays. From October to March, the sun is too weak for most people to make enough, which is why deficiency is common. ## Symptoms of deficiency Many people with low vitamin D feel **no symptoms**. When symptoms occur, they may include: - tiredness and general aches - bone pain — especially lower back, pelvis, hips and legs - muscle weakness — difficulty climbing stairs or getting up from a chair - mood changes — low mood (research links deficiency to depression, though cause is unclear) - frequent infections **Severe deficiency** causes **rickets** in children (soft, bowing bones) and **osteomalacia** in adults (bone pain and weakness from softened bones). These are uncommon in the UK today but still occur. ## Who is at higher risk - people with darker skin — more melanin reduces vitamin D production - people who cover most of their skin outdoors for cultural or religious reasons - those who are housebound or in care homes - people with malabsorption — coeliac disease, Crohn’s disease, after bariatric surgery - obesity — vitamin D is stored in fat and less available - older adults — skin produces vitamin D less efficiently ## NHS supplementation advice Current UK guidance: - All adults should consider 10 micrograms (400 IU) daily from October to March - At-risk groups should take supplements year-round - Breastfed babies need vitamin D drops from birth (formula is fortified) - Children aged 1–4 need 10 micrograms daily year-round Supplements are widely available from pharmacies and supermarkets. Vitamin D3 (cholecalciferol) is generally preferred over D2. ## Diagnosis and treatment A GP may test vitamin D levels if you have symptoms and risk factors. Blood tests measure 25-hydroxyvitamin D: - Deficient — usually below 25 nmol/L — treated with higher prescribed doses for 6–8 weeks, then maintenance - Insufficient — 25–50 nmol/L — maintenance supplementation - Sufficient — above 50 nmol/L You do not need a blood test before starting a standard preventive supplement. ## Food sources Diet provides limited vitamin D: - oily fish — salmon, sardines, mackerel - egg yolks - fortified foods — some cereals, margarine, milk alternatives Sunlight and supplements remain more important than diet alone in the UK climate. ## Safe supplementation Stick to recommended doses. **Do not** take very high doses without medical supervision — excess vitamin D causes hypercalcaemia (high calcium), which can damage kidneys and bones. The NHS maintenance dose of 10 micrograms daily is safe for long-term use. ## Vitamin D and other conditions Low vitamin D is associated with **tiredness** and may contribute to muscle and bone pain mistaken for other conditions. Correcting deficiency sometimes improves symptoms, though tiredness has many causes — see our tiredness guide if symptoms persist after treatment. Deficiency is also linked to **osteoporosis** risk in older adults alongside calcium intake and exercise. ## Getting sensible sun exposure In summer, brief sun exposure on forearms and lower legs without sunscreen — about 10–15 minutes for lighter skin, longer for darker skin — helps maintain levels. Avoid burning. Balance sun exposure with skin cancer risk — supplements cover winter gaps safely. ## ! When to see a GP about vitamin d deficiency See a GP if you have persistent bone pain, muscle weakness, frequent falls, or symptoms of deficiency alongside risk factors — limited sun exposure, dark skin, malabsorption conditions, or obesity. A blood test confirms deficiency. Seek urgent help for severe bone pain in children or bowing of leg bones (possible rickets). ## Common questions about vitamin d deficiency What are the symptoms of vitamin D deficiency? Many people have no obvious symptoms. When present, they include tiredness and general aches, bone pain especially in the lower back, pelvis and legs, muscle weakness, mood changes, and frequent infections. Severe deficiency causes rickets in children and osteomalacia (soft bones) in adults. Who should take vitamin D supplements in the UK? The NHS recommends all adults consider 10 micrograms (400 IU) daily from October to March. Year-round supplementation is advised for people who get little sun exposure, have dark skin, cover their skin outdoors, or are in care homes. Can I get enough vitamin D from food? Only a small amount comes from diet — oily fish, egg yolks, fortified cereals and spreads. Sunlight remains the main source for most people, which is why UK guidance emphasises supplements in winter. How is vitamin D deficiency treated? A GP confirms deficiency with a blood test and prescribes higher-dose supplements for a period, then maintenance doses. Over-the-counter supplements prevent deficiency in most people without needing a blood test first. Can you take too much vitamin D? Yes. Very high doses over long periods can cause calcium build-up and harm kidneys and bones. Stick to recommended doses — 10 micrograms daily for maintenance, or as prescribed by a GP for treatment. ## Sources - [NHS — Vitamin D](https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/) - [NICE — Vitamin D deficiency](https://cks.nice.org.uk/topics/vitamin-d-deficiency-in-adults/)