Muscular and joint health: The vitamin D gap in our joints

Arthritis and autoimmune diseases affect millions of people around the world, but their heavier impact on the Black community often goes unnoticed. In this piece I want to explain what these conditions are, why they affect us differently, how vitamin D fits in, and what you can do to protect your muscles, bones and joints.

Aisha's story

Let me start with a case scenario. Aisha Thompson is a 32-year-old Black British teacher. She used to love her work, her activities and her hobbies. But she began to have persistent muscle and joint pain, especially in her shoulders, back and knees. It affected her quality of life, and she could no longer teach as effectively as she used to.

Aisha went to her GP practice several times, and each time she felt her concerns were being minimised. Eventually she was referred to a rheumatologist, a specialist in joint and autoimmune conditions, and she was diagnosed with vitamin D deficiency and rheumatoid arthritis.

Aisha is not a real patient, but her experience will sound familiar to many Black people: symptoms that build up quietly, repeated appointments, and a sense of not being taken seriously before the right diagnosis finally comes.

Arthritis and autoimmune disease, explained simply

Arthritis is a group of joint disorders that cause pain and stiffness, and it can get worse with age. Autoimmune diseases happen when the immune system mistakenly attacks the body's own healthy cells. Depending on which cells are attacked, they can affect many different parts of the body, and they can develop at any age. Rheumatoid arthritis, which Aisha has, is both: an autoimmune disease that attacks the joints.

Some of these conditions are more common, and often more severe, in Black people:

• In England and Wales, Black patients with early inflammatory arthritis are less likely than white patients to reach remission in the first months after diagnosis, even after allowing for delays.
• Some autoimmune diseases are more common and more severe in the Black community. Lupus, for example, is two to three times more common in Black women than in white women in the US, and LUPUS UK notes that it is more common, and can be more severe, in people of Black African and Black Caribbean heritage.

Why vitamin D matters so much

Vitamin D deficiency can cause muscle weakness and fragile bones. It has also been associated with a higher risk of conditions such as rheumatoid arthritis and lupus. Research, including a large US study in the Journal of the American Medical Association, has linked higher vitamin D levels with a lower risk of multiple sclerosis, an autoimmune disease that damages the nerves. It is not yet proven that taking supplements prevents MS.

This is where Black people are particularly affected. A large US study found that 82% of Black adults had low vitamin D levels, and other US surveys have found deficiency is several times more common in Black adults than in white adults. The reason is our skin: the higher melanin in Black skin reduces how much vitamin D we produce from sunlight. Researchers are still studying whether that shortfall contributes to the higher rates of some autoimmune diseases, such as lupus, in our community, but addressing it is important for bone and muscle health either way.

The barriers to diagnosis and treatment

Black people face several specific challenges in getting muscle and joint problems diagnosed and treated:

1. Lack of representation in clinical trials. When we are underrepresented in research, treatments are not always tested in people like us.
2. Socioeconomic factors. Many of us work in more physical jobs, which put extra strain on the body, and many work in jobs where we cannot afford to take time off to see a GP.
3. Cultural competency of healthcare professionals. As Aisha's story shows, feeling ignored or dismissed can delay a diagnosis for months or years.
4. Vitamin D deficiency itself, which is so common and so often missed.

How to improve your vitamin D levels

• Get enough sunlight. Because of our melanin, we need longer in the sun to make the same amount of vitamin D. In a UK summer, short daily spells of sun on bare arms and legs, without burning, help, but many people with dark skin still do not make enough, which is why a supplement matters. If you are lucky enough to live in Africa or the Caribbean, make the most of the daily sunshine.
• Take a supplement when sunlight is scarce. In colder countries, it is much harder to get enough sun in winter. In the UK, the NHS advises everyone to consider a daily vitamin D supplement in autumn and winter, and people with darker skin, including those of African or African-Caribbean heritage, should consider taking 10 micrograms (400 IU) a day all year round. Do not take more than 100 micrograms (4,000 IU) a day unless your doctor advises it.
• Eat a balanced diet with plenty of variety.
• Have regular check-ups. Know your blood results, including your vitamin D and iron levels.

Lifestyle changes that protect your joints

Lifestyle modifications play an important part in managing arthritis and autoimmune disease.

Exercise and physical activity. Arthritis can come from repeated wear and tear, but it is still important to exercise our bones and joints. Different types of exercise do different jobs:

• Strength training increases bone density.
• Aerobic exercise, such as swimming and running, improves your cardiovascular system. People often forget that bone is rich in blood vessels, so good circulation benefits your bones too. Swimming is a great non-weight-bearing option if your joints are painful.
• Flexibility exercises keep tendons, ligaments and joints supple.
• Balance exercises, such as tai chi, help prevent falls as we get older.

Dietary adjustments. Aim for a varied, balanced diet with plenty of fruit and vegetables, and drink plenty of water. Try to cut down on inflammatory foods, including heavily salted foods.

Foods to avoid. Everyone is different, so talk to your doctor or a dietitian about which foods may be aggravating your symptoms.

Stress belongs in this conversation too

There is one more factor I want every Black person to hear. We must acknowledge and address the impact of chronic stress, a high trauma load and lifestyle on the risk of arthritis and autoimmune disease in the Black community. What we carry emotionally does not stay in the mind. Over time, it shows up in the body as well.

Signs worth raising with your GP

Muscle and joint problems often start gradually, so it helps to know what to look out for. Book an appointment if you notice:

• Joint pain or stiffness that lasts more than a few weeks
• Stiffness that is worse in the morning or after resting
• Joints that are swollen, warm or tender
• Muscle weakness or aches that do not settle
• Ongoing tiredness that rest does not fix
• Pain that stops you working, exercising or doing everyday tasks

Keep a note of when your symptoms started, which joints are affected and what makes them better or worse. It will help your doctor, and it will help you explain what you are experiencing if you feel you are not being heard.

What to take away

If you have persistent muscle or joint pain, stiffness, or unexplained tiredness, do not accept being brushed off. Ask about your vitamin D level. Ask whether arthritis or an autoimmune condition could be the cause, and ask to be referred if your symptoms are not improving.

And whatever your age, protect your future joints now: get some sun when you can, take vitamin D when you cannot, keep moving in ways your body enjoys, and look after your stress as seriously as you look after your diet.