Chronic pain among women may be down to low levels of vitamin D

According to new research published ahead of print, low vitamin D levels may contribute to chronic pain in women.

Vitamin D the "sunshine vitamin", is essential for healthy bones, and is produced in the body when exposed to sunlight and is also found in oily fish, egg yolks and margarine.

The research was based on the blood analyses and pain scores of almost seven thousand 45 year old men and women from across England, Scotland and Wales, who were all born during one week in March 1958.

The research revealed that smokers, non-drinkers, the overweight and the underweight all reported higher rates of chronic pain and while the extent of the chronic widespread pain did not vary among men according to vitamin D levels, this was not the case for women.

Women with vitamin D levels between 75 and 99 mmol/litre had the lowest rates of this type of pain, at just over 8%, whereas women with levels of less than 25 mmol/litre had the highest rates, at 14.4%.

The research team from the Institute of Child Health in London say there appeared to be a J shaped curve, with the prevalence of widespread pain at 10% or higher among those with vitamin D levels above 99 mmol/litre.

The researchers say the findings were not explained by gender differences, lifestyle or social factors, such as levels of physical activity and time spent outdoors and at the age of 45, few of the women would have entered the menopause, when bone mineral density falls as oestrogen levels drop.

The researchers say one possible explanations might be osteomalacia, a disease of extreme vitamin D deficiency, which is associated with isolated or generalised bone pain.

The hormonally active form of vitamin D is also involved in the regulation of immune system responses and the scientists say around 1 in 10 people suffer from chronic widespread pain at any one time.

They say while the causes are not fully understood, social and psychological factors are thought to affect the sensation and reporting of pain and studies are now needed to see if vitamin D supplements can guard against chronic pain.

The research is published ahead of print in the Annals of the Rheumatic Diseases.