Vitamin D deficiency: why is it common despite the sun?

What is vitamin D?

Vitamin D helps the body absorb calcium and keep bones and muscles healthy, and it has other roles that are still being studied. The body gets it mainly from sunlight on the skin, and also from some foods and supplements.

Why is it common despite the sun?

• Spending most of the day indoors in air-conditioned spaces, and avoiding the sun because of the heat.
• Covering most of the skin with clothing.
• Darker skin needs longer in the sun to produce the same amount.
• Few foods rich in vitamin D in the diet.
• Health factors such as obesity, some digestive, kidney and liver conditions, and some medications.

Does it cause symptoms?

Often there are no clear symptoms. Severe or long-lasting deficiency may be linked to tiredness, bone or muscle pain, and muscle weakness. These symptoms are general and have many other causes, so feeling them is not enough to conclude that you are deficient.

How is it detected?

It is detected with a blood test that measures your vitamin D level, usually called 25-hydroxy vitamin D. Your doctor orders it when there is a reason to, and interprets the result in the context of your age, your condition and the medicines you take. Reference ranges may differ from one laboratory to another.

General tips

• Moderate, safe sun exposure at suitable times, avoiding the hottest hours. Read heat safety tips.
• Vary your diet with sources such as oily fish, eggs and fortified foods.
• Keep your previous test results to follow changes over time.

Where does HealTrip fit in?

HealTrip is working to bring your test results, your doctor and your record together in one place, so each result is read in context and you know your next step clearly, while the medical decision stays with the specialist doctor.