15050 Vitamin D Vitamin D Deficiency

Overview

Vitamin D deficiency means your body does not have enough vitamin D. Vitamin D is a nutrient that helps your body absorb calcium, which keeps your bones strong. It also helps your muscles, heart, and immune system work properly.

Yes, vitamin D deficiency is common around the world. It occurs more often in people who live in northern areas, get little sunlight, or have darker skin.

It can affect anyone, but it is more common in older adults, people who are housebound or cover their skin, people with darker skin, people who are overweight, and people with digestive conditions that affect nutrient absorption.

Symptoms

Common symptoms

• Feeling tired or low on energy
• Bone pain or aching bones
• Muscle weakness or cramps
• Low mood or feeling down
• Frequent infections

Symptoms in children

• Soft or weak bones (a condition called rickets)
• Slow growth or short height
• Late teething or delay in walking
• Irritability or fussiness

Symptoms in older adults

• More falls or trouble balancing
• Bone fractures, especially hip fractures
• Muscle aches and weakness
• Difficulty climbing stairs or getting up from a chair

Causes

Main causes

• Not getting enough sunlight on your skin
• Eating a diet that is low in vitamin D
• Having a digestive problem that makes it hard to absorb vitamin D
• Having kidney or liver disease that affects vitamin D activation

Risk factors

• Living far from the equator or in places with long winters
• Having darker skin, because more pigment means less vitamin D made from sunlight
• Being older, as your skin makes less vitamin D as you age
• Being overweight or obese
• Wearing clothing that covers most of your skin
• Staying indoors for long periods, such as in care homes

When to see a doctor

See a doctor urgently if:

• If you have seizures, severe muscle spasms, chest pain, or trouble breathing, call your local emergency number right away.
• If you have severe bone pain or muscle weakness that stops you from standing or walking, get same-day medical help.

Book a routine appointment if:

• If you have ongoing tiredness, bone pain, or muscle weakness, make an appointment with your doctor.
• If you have a condition or take medicines that put you at risk for low vitamin D, ask whether a test might be a good idea.

Diagnosis

Doctors diagnose vitamin D deficiency with a simple blood test. The blood sample is tested for a form of vitamin D called 25-hydroxyvitamin D.

Tests that may be done

• Blood test for 25-hydroxyvitamin D
• Sometimes bone density tests if there are concerns about bone health

What to expect at your appointment

A nurse or doctor will take a small blood sample from a vein in your arm. It takes only a few minutes. You may need to wait a few days for the results. Your doctor will explain your level and what it means for you.

Treatment

Treatment aims to bring your vitamin D levels back to normal and prevent symptoms. This is usually done with vitamin D supplements, along with changes to your diet and lifestyle.

Self-care at home

• Spend short periods in the sun, aiming for a few minutes a day on bare skin without burning.
• Eat foods rich in vitamin D, such as oily fish, egg yolks, mushrooms, and fortified foods.
• Follow your doctor's advice about the right supplement dose – never take extra without medical guidance.

Medical treatments

Your doctor may recommend a vitamin D supplement in a specific form and strength that depends on your blood test result and your health. Treatment is usually taken for several weeks to months, and then a lower maintenance dose may be used. Do not take high doses of vitamin D without your doctor's supervision, as too much can be harmful.

When is surgery considered?

Surgery is not used to treat vitamin D deficiency.

Living with this condition

It may take a few months for your vitamin D levels to return to normal. During this time, keep taking your prescribed supplements and follow your doctor's advice. Stick to a routine so you do not forget your daily or weekly dose.

Lifestyle tips

• Keep a regular schedule for taking your vitamin D supplement if prescribed.
• Spend time outdoors safely, even in winter, on days when the sun is out.
• Maintain a healthy weight and stay active with walking, dancing, or other gentle exercises.
• Avoid alcohol and smoking, which can affect bone health.

Diet and exercise

Eat a balanced diet that includes vitamin D–rich foods, such as salmon, sardines, and fortified cereals. Weight-bearing exercise like walking, jogging, or lifting light weights helps build and maintain bone strength.

Mental health and emotional wellbeing

Low vitamin D has been linked to low mood, and some people feel depressed or anxious. Treating the deficiency may improve how you feel. If you are struggling, talk to your doctor or a mental health professional for support.

Prevention

In most cases, yes. You can prevent vitamin D deficiency by getting safe, regular sunlight exposure, eating foods rich in vitamin D, and taking a supplement if your doctor recommends it, especially during autumn and winter.

Vaccines

There is no vaccine for vitamin D deficiency.

Screening programmes

Routine screening is not recommended for everyone, but your doctor may check your vitamin D level if you have risk factors or symptoms. Speak to your doctor about whether testing is right for you.

Complications

If left untreated

• Weak and painful bones, called osteomalacia in adults
• Soft and deformed bones in children, called rickets
• Increased risk of falls and fractures in older adults
• Muscle weakness that can affect daily activities

Long-term outlook

With the right treatment, most people recover fully. Bone pain and muscle weakness usually improve within weeks to a few months. Once your levels return to normal, keeping up healthy habits can protect your bones and overall health for years to come.

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