It sounds odd at first. We live under some of the strongest sunshine on earth, in Riyadh, Jeddah, Karachi or Lahore, and yet low vitamin D is something doctors talk about all the time. Here is a plain guide to vitamin d deficiency symptoms, why sunny countries are not protected, and what to do if you are worried.
Quick answer
Short answer: Low vitamin D can cause bone pain, muscle aches or weakness, and in the long run softer, weaker bones. Many people have no clear symptoms at all. Covering most of the skin, staying indoors, darker skin and some health conditions all raise the risk, even in hot countries. The reliable way to know is a blood test, so talk to your doctor.
Key takeaways
- Why it matters: vitamin D helps the body absorb calcium for healthy bones, and muscles and nerves need it too.
- Symptoms can be quiet: MedlinePlus notes that low levels may weaken bones even if you don't have symptoms.
- Sunshine isn't enough on its own: a review of 16 studies of healthy Saudi adults (2008 to 2015) found an overall deficiency rate of 63.5%.
- Testing is the answer: a blood test measuring 25-hydroxyvitamin D shows whether your level is low.
What vitamin D does in the body
Vitamin D helps your body absorb calcium and phosphate, which are needed for healthy bones, teeth and muscles. According to MedlinePlus, your muscles need it to move, your nerves need it to carry messages, and your immune system needs it too.
Your skin makes vitamin D when bare skin is exposed to sunlight outdoors. A small number of foods also contain it, such as egg yolks, oily fish and liver, along with some fortified foods.
Common vitamin D deficiency symptoms
This is where it gets tricky. Low vitamin D often develops slowly, and the signs can be vague or easy to blame on a busy life.
MedlinePlus lists these as signs that may be linked to low vitamin D:
- bone pain
- muscle weakness or aches
- soft or deformed bones
- weak bones and fractures
Over time, a long-term lack can lead to a condition called osteomalacia in adults, which causes bone pain and muscle weakness. In children, it can cause rickets, where bones become soft and weak.
People often wonder about tiredness or low mood. These can have many causes, and the NIH Office of Dietary Supplements notes that the research on vitamin D and mood is still mixed. So please don't assume, and don't self-diagnose. Let a doctor look at the whole picture.
Why it's common even in sunny countries
Sunshine is only half the story. What matters is how much sunlight actually reaches bare skin, and how well the body can make and use vitamin D.
A review of Saudi studies asked this very question: why would people in a sunny climate have low levels? Researchers pointed to several possible reasons, including inactivity, obesity and chronic illness.
Everyday life plays a part too. When summer afternoons turn scorching, most of us sensibly stay in air-conditioned homes, offices and cars. Sunlight through a window does not help the skin make vitamin D, as the NIH notes.
You may be more likely to run low if you
- Spend most of the day indoors, at home or at work
- Usually wear clothes that cover most of your skin when outdoors
- Have darker skin, for example a South Asian or African background
- Are older, as skin makes less vitamin D with age
- Have a condition affecting fat absorption, such as coeliac or Crohn's disease
- Have had weight-loss surgery, or take certain medicines your doctor knows about
Covering up for modesty or sun protection is a completely valid choice. It simply means it is worth being more aware of vitamin D and checking with your doctor.
What to do if you think your level is low
The honest answer is simple: get a blood test and talk to your doctor. Symptoms alone cannot tell you your vitamin D level.
Next steps, in order
1
Note your symptoms: write down any bone or muscle aches and how long they have lasted.
2
Book a doctor's appointment: mention your symptoms, daily routine and any medicines you take.
3
Ask about a blood test: your doctor can decide if a 25-hydroxyvitamin D test is right for you.
4
Follow their advice: your doctor will explain your result and what, if anything, to change.
MedlinePlus explains that routine testing is not recommended for everyone, which is another reason to let your doctor guide you.
Please don't self-prescribe
Taking too much vitamin D from supplements over a long time can be harmful, according to the NHS and NIH. You cannot get too much from sunshine, but high-strength supplements are a different matter. Only take what your doctor advises.
Small everyday habits that may help support healthy levels
Alongside your doctor's advice, a few gentle habits may help. Some families enjoy a short walk together in the early morning or after Maghrib, when the heat is kinder. Eggs and oily fish can be part of a balanced home menu.
Keep sun safety in mind too. MedlinePlus notes that too much sun can damage the skin, so avoid the harsh midday sun and don't burn. Your doctor can help you find the right balance for your skin and lifestyle.
This article is educational and is not medical advice. Talk to your doctor about your own health.
Last checked: 6 October 2026
