How vitamin D deficiency is linked to chronic pain

Scientists are still untangling the riddle of chronic pain. Everyone who suffers chronic pain has different symptoms and triggers. A treatment that works for one person, may not work for another person.

It is frustrating for the chronic pain sufferers - they must test a large number of treatments to find the ones that help them the most. And this may change over time. It's also frustrating for the scientists and doctors, as there seems to be no single cause and therefore no single treatment.

In the last 5 years, increasingly more research has been performed into vitamin D levels in sufferers of chronic pain, specifically those with fibromyalgia syndrome. Some of these studies have shown that those with chronic pain have reduced vitamin D levels, but they don't yet understand why.

Although it has not yet been proven that increased vitamin D intake reduces pain, the longer term benefits of maintaining a stable normal level of vitamin D, after being diagnosed with a deficiency, is a good reason that doctors recommend that chronic pain sufferers take supplements.

Pain becomes chronic when it persists for more than 3-6 months, although some doctors classify it as chronic pain only after 12 months. There is often no obvious physical sign of the pain, and sufferers are often told it's all in their head.

Chronic pain can be caused by such a multitude of diseases and physical problems. Nerve problems, brain chemistry problems, inflammation, breakages, viruses, even past injuries - almost anything can cause long term pain.

Each person's journey through diagnosing and living with chronic pain, finding treatments that help them manage, will be different. Some researchers are looking at how vitamins may affect how a person's brain perceives pain, as it seems that chronic pain sufferers often have different levels of vitamins to people who are 'healthy'.

There are theories that vitamin D is used faster for those in chronic pain as their immune systems are under constant stress. But this has not yet been proven.

Vitamin D is important for healthy bone growth and repair. It plays an important role in preventing osteoporosis as we age.

Levels are tested by taking a blood sample. Each laboratory may use a different testing method, and the 'normal' range for reference is included in the blood test report.

Vitamin D is created in the kidneys, from foods that we eat. Foods higher in vitamin D include:

• fatty fish such as catfish, salmon, mackerel, sardines, trout, tuna, and oysters
• fish liver oils
• shiitake, portabella and other types of mushrooms, when grown in sunlight or under UV lights
• whole eggs

The recommended intake from food or supplements varies between countries. The range of recommended levels start from the European Union's 200 IU/Day (5.0 μg/day), to Canada's recommendation for those over 70 to have 800 IU/day (20 μg/day).

For adults, including those who are pregnant or breastfeeding, the upper 'safe' limit is set at 4,000 IU (100 μg/day). Taking more than 50,000 IU/day (250µg/day) risks vitamin D poisoning, however, this is unlikely to happen without tablet supplementation.

In recent years, many health professionals have claimed that vitamin D deficiency is on the rise, thanks to longer working hours spent indoors.

When a person's diet does not contain enough vitamin D, and they do not have enough skin-exposure to sunlight, then vitamin D levels may decline, and eventually become deficient.

A vitamin D deficiency can cause bone demineralisation (rickets in children, osteomalacia in adults), osteoporosis, as well as weak, aching and twitching muscles. Scientific American published an article linking vitamin D deficiency to an increase in risk of colds and the flu in winter, especially for those with underlying respiratory problems. Other health professionals have claimed that a variety of diseases are caused by or made worse by low levels of vitamin D.

Some daily skin exposure sunlight is important for the body to manufacture a healthy level of vitamin D, but some care must be taken.

Humans create vitamin D in the skin when exposed to 'sufficient' sunlight (UVB). This occurs usually when the UV index is above 3, which is more commonly in summer and late spring/early autumn or year-round in tropical areas.

Studies show that reduced exposure to sunlight causes a decrease in vitamin D levels. In modern society, many people work inside during the day, and are exposed to very little sunlight, resulting in the increase in lower levels of vitamin D.

Anti-cancer societies encourage the constant use of high-protection sunscreen lotions, as skin cancer rates rise worldwide. However, as sunscreen blocks UV rays and prevents vitamin D production in the skin, this may contribute to the growing number of vitamin D deficient people. It is difficult to determine where the happy medium lies.

It has also been shown that sunlight is important for those suffering from depression. Many chronic pain sufferers also deal with depression - being in pain all of the time is not easy to handle.

It is not known if the chronic pain causes a reduction in vitamin D levels, or whether the low levels cause more pain. It is not even proven that such a direct link in either direction exists, yet research seems to indicate there is some relationship between long-term pain and vitamin D.

An Australian study and the Mayo clinic have both suggested that supplementing vitamin D helps to reduce or stop the wind-up response in chronic pain sufferers, where the pain-threshold is lowered by constant pain signals over-sensitizing pain receptors in the brain. This may be useful for those suffering fibromyalgia, known for having a particularly strong wind-up response.

Although many studies have not proven that vitamin D supplementation helps chronic pain, supplementation with vitamin D3 is inexpensive. Doctors may choose to prescribe supplements for those who have tested low levels, both for the possible pain reduction, and for the longer term protection of bone health.

I am not a medical professional. If you have pain of any kind, or are considering supplementing your diet with vitamin D tablets, please contact your doctor.

I have been diagnosed with multiple chronic pain conditions, including fibromyalgia, adenomyosis, and various other inflammatory and nerve conditions. I also have an extremely low (and difficult to raise) vitamin D level, which some doctors and pharmacists had mentioned was linked to the chronic pain conditions.