Vitamin D Deficiency
Sources consulted
This article is original patient-education content.
- WHO—Health topics A–Z(2024)
- NHS—Health A to Z(2024)
- CDC—Health topics(2024)
Based on international clinical guidelines
Overview
Vitamin D deficiency is when your body doesn't have enough vitamin D, a nutrient that helps absorb calcium and keep bones, teeth, and muscles healthy. Without enough vitamin D, bones can become thin, brittle, or soft.
Key facts
- Vitamin D is made by the skin when exposed to sunlight, but many people don't get enough sun.
- It is also found in foods like oily fish, eggs, and fortified foods.
- A simple blood test can check your vitamin D level.
Yes, vitamin D deficiency is very common worldwide. It affects people of all ages, especially those who live in northern climates, have darker skin, or spend little time outdoors.
It can affect anyone, but is more common in older adults, people with darker skin, those who are housebound or cover their skin, people with certain medical conditions (like Crohn's disease or kidney disease), and those who are obese.
Symptoms
- If you have sudden, severe muscle spasms or cramps that do not stop
- If you feel numbness or tingling around your mouth or in your fingers and toes
- If you have a seizure or difficulty breathing (these can happen in very severe deficiency with low calcium)
- ⚠If you have persistent bone pain that limits your daily activities
- ⚠If you have muscle weakness that makes walking or lifting objects difficult
Common symptoms
- Feeling tired or weak
- Bone or muscle pain, especially in the back, hips, or legs
- Mood changes, such as feeling down or depressed
Symptoms in children
- Soft or weak bones that can bend (rickets)
- Delayed growth or not reaching developmental milestones
- Muscle cramps or twitching
Symptoms in older adults
- Increased risk of falls and fractures
- Bone pain that feels like a deep ache
- Muscle weakness, especially in the legs
Causes
Main causes
- Not enough sunlight exposure (especially in winter or if you cover your skin)
- Not getting enough vitamin D from food or supplements
- Problems with absorption in the gut (e.g., Crohn's disease, coeliac disease, after weight loss surgery)
- Kidney or liver disease that makes it hard for the body to convert vitamin D into its active form
Risk factors
- Living in a country far from the equator (less sun)
- Having naturally dark skin (more melanin reduces vitamin D production)
- Being elderly or housebound
- Being pregnant or breastfeeding without taking vitamin D supplements
- Taking certain medicines that affect vitamin D metabolism (like some epilepsy drugs or steroids)
When to see a doctor
See a doctor urgently if:
- If you have any of the emergency symptoms listed above
- If your child has signs of rickets (bowed legs, soft skull, or slow growth)
Book a routine appointment if:
- If you have ongoing fatigue, bone pain, or muscle weakness that lasts more than a few weeks
- If you belong to a high-risk group and want to have your vitamin D level checked
- Before you start taking high-dose vitamin D supplements (it's safer with medical advice)
Diagnosis
A simple blood test called 25-hydroxyvitamin D test. Your doctor will take a small sample of blood and send it to a lab. The result tells you your vitamin D level.
Tests that may be done
- Blood test for 25-hydroxyvitamin D (the main form stored in the body)
- Sometimes additional tests: blood calcium, phosphorus, and parathyroid hormone to check for related problems
What to expect at your appointment
The test takes only a few minutes. You don't need to stop eating or drinking beforehand. Results usually come back in a few days. Your doctor will explain if your level is low, normal, or high, and what to do next.
Treatment
Treatment focuses on raising your vitamin D level to a healthy range. This can usually be done with a combination of safe sun exposure, dietary changes, and vitamin D supplements. Always follow your healthcare provider's advice on the right approach for you.
Self-care at home
- Get safe sunlight on your skin: aim for 10 to 30 minutes a day on arms and legs (without sunscreen) during midday, depending on your skin type and location. Avoid burning.
- Eat foods rich in vitamin D: oily fish (salmon, mackerel, sardines), egg yolks, liver, and fortified foods (some milk, cereals, and orange juices).
- Take a vitamin D supplement as recommended by your doctor. Do not take more than advised without medical supervision.
Medical treatments
Your doctor may recommend a vitamin D supplement in a specific dose for a set period. They might also treat an underlying condition that is causing the deficiency (like malabsorption). In severe cases, high-dose oral supplements or, rarely, vitamin D injections may be used – always under medical guidance.
When is surgery considered?
Surgery is not used to treat vitamin D deficiency itself. However, if the deficiency is caused by a condition that requires surgery (such as a tumour in the parathyroid gland), that may be addressed separately.
Living with this condition
Once your vitamin D level returns to normal, you can maintain it with regular, sensible sun exposure and a balanced diet. If sun exposure is limited, you may need to continue a daily low-dose supplement. Your doctor will advise on long-term maintenance.
Lifestyle tips
- Aim to spend time outdoors most days, even in winter – a short walk can help.
- Consider a vitamin D supplement during autumn and winter if you live in a northern country.
- Wear sunscreen after a few minutes of sun to protect your skin, but don't overdo it – a little sun is good for vitamin D.
Diet and exercise
Eat a varied diet that includes vitamin D-rich foods. Weight-bearing exercise (like walking, jogging, or lifting weights) helps keep your bones strong. Always check with your doctor before starting a new exercise programme, especially if you have bone pain.
Mental health and emotional wellbeing
Low vitamin D has been linked to low mood and depression. Correcting a deficiency may help improve your mood. If you feel depressed, talk to your doctor – they can support you and check for other causes too. If you are having thoughts of harming yourself, call your local crisis helpline or emergency services immediately.
Prevention
Yes, for many people. Getting regular, safe sun exposure and eating a diet with vitamin D-rich foods can help prevent deficiency. For people at high risk (older adults, dark skin, housebound), a daily supplement may be recommended. The NHS advises everyone in the UK to consider a daily supplement of 10 micrograms (400 IU) during autumn and winter.
Screening programmes
Routine screening of the general population is not typically recommended. However, your doctor may suggest a blood test if you have symptoms or are at high risk.
Complications
If left untreated
- Soft, weak, or deformed bones (osteomalacia in adults, rickets in children)
- Increased risk of falls and fractures, especially in older adults
- Weakened immune system, leading to more frequent infections
- Possible link to chronic diseases like heart disease, diabetes, and some cancers (more research is needed)
Long-term outlook
The outlook is excellent for most people. With treatment, vitamin D levels usually return to normal within a few months, and symptoms like bone pain and fatigue improve. Bones become stronger, and the risk of fractures goes down. By taking simple steps to maintain healthy levels, most people can prevent future problems.
Find support
International organisations
Local organisations
- NHS (UK) – Vitamin D ↗ · United Kingdom
Helplines
External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.
Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.