A vitamin D deficiency can affect both physical and mental health, but many people have low levels of vitamin D without realizing. The physical symptoms of a deficiency may include muscle pain in the joints, including rheumatoid arthritis (RA) pain, which often occurs in the knees, legs, and hips.
In this article, we look at the evidence for a link between vitamin D and joint pain. We discuss how people can obtain vitamin D and what their daily intake should be.
Why do we need vitamin D?
The body can create vitamin D through exposure to sunlight.
Vitamin D is a nutrient that helps regulate the amount of calcium in the body. This vitamin is crucial for bone health.
A deficiency of vitamin D causes bones to soften and become weak. This is called osteomalacia in adults and rickets in children. Vitamin D can also help prevent osteoporosis, which is another condition that weakens bones.
Symptoms of vitamin D deficiency vary from person to person. Typical symptoms include:
- joint pain
- muscle pain and weakness
- bone pain
- respiratory issues
- neurological concerns including numbness
- low mood, specifically seasonal affective disorder (SAD)
Vitamin D and joint pain
Vitamin D is vital for bone and muscle function and may have anti-inflammatory effects. As a result, many people believe that vitamin D plays a role in relieving joint pain, particularly where inflammation is the cause.
Some research links vitamin D deficiency to RA, which is a chronic inflammatory condition that affects the joints.
- A review of studies from 2016 showed that people with RA had notably less vitamin D in their blood than people without RA. They also found that people with RA were more likely to have a vitamin D deficiency.
- A research paper from 2012 suggests that vitamin D deficiency may be a risk factor for the onset of inflammatory diseases such as RA and that it may increase the condition's severity.
- Vitamin D supplementation is beneficial for the prevention of osteoporosis. RA sufferers have a higher risk of osteoporotic fractures and experience greater joint pain, so supplementation is advisable.
- Vitamin D may also help improve mood and symptoms of depression.
However, a large-scale Cochrane study from 2015 concluded that the current evidence is not strong enough to establish a definite link between vitamin D deficiency and chronic pain conditions such as RA. Therefore, researchers need to provide more evidence.
How to get vitamin D
The body can either create vitamin D through exposure to sunlight or obtain vitamin D from the diet. Key sources of vitamin D include:
When exposing bare skin to the sun, the body can make vitamin D from ultraviolet B (UVB) light.
Although sunlight is an excellent source of the vitamin, it is essential to avoid hot, midday sun to prevent burning. Overexposure can cause skin damage and increase the risk of skin cancer.
When spending time in the sun is more difficult, such as during the winter months, it is much harder to get a sufficient amount of vitamin D from sunlight, so it may be necessary to obtain this vitamin from dietary sources instead.
Mushrooms are rich in vitamin D.
The National Institutes of Health (NIH) recommend that adults have 15 micrograms (mcg) of vitamin D per day.
The foods below are some of the few that are rich in vitamin D, so the diet should include some of these each day if possible:
- oily fish, such as salmon, mackerel, and tuna
- fortified milk
- beef liver
- egg yolks
- fortified breakfast cereals
Some people, such as vegetarians or older adults, may struggle to get enough vitamin D, especially in the winter.
The NIH suggest that supplements may be useful for:
- older adults, as the skin loses its ability to synthesize vitamin D as effectively
- people with darker skin, as it may be more difficult for the skin to use sunlight for vitamin D production
- breast-fed infants, as their vitamin D status relies on another person's
It is possible to obtain vitamin D supplements from drugstores or online.
Too much vitamin D can cause toxicity, so it is best to talk with a doctor or healthcare professional before taking any new supplements and to adhere to the dosage they recommend.
Other vitamins for joint pain
Joint pain is often a sign of inflammation. While there is still a lack of understanding around the role of food in mediating joint pain, people should not overlook the impact of diet and specific nutrients.
Other nutrients that might help relieve joint pain include:
- probiotics, according to a 2017 study, where an autoimmune disease is the cause of the pain
- omega-3 polyunsaturated fatty acids, according to a 2017 study
- vitamin K
Additionally, a diet rich in antioxidants from brightly colored fruit, vegetables, nuts, and seeds can boost overall health and reduce the risk of disease.
Vitamin D deficiency is common, but exposure to natural sunlight and eating foods rich in vitamin D can help prevent the condition.
Vitamin D deficiency seems to be prevalent in patients with RA, and lower vitamin D levels may also contribute to the severity of joint pain. However, there needs to be more research in this area.