A 58-year-old woman has virtually no vitamin D in her blood due to a never-before-seen genetic mutation.
The woman – who has not been named – went to her doctor complaining of pain in her back, neck, shoulders and hips, which she had endured since she was a teenager.
She had also lost 20cm in height over the years, as well as enduring broken ribs, arms and hips after minor falls.
A blood sample revealed the woman – who lives in Canada – had 'almost undetectable levels of vitamin D'.
A DNA test showed she does not carry a gene that enabled the vitamin to be transported by the blood.
Her parents – who were second cousins – were both carriers of this gene, with her inheriting the 'faulty' DNA from them both.
Treatment with oral and injectable vitamin D over many years helped boost her vitamin D levels, but they have never reached normal amounts.
A woman has virtually no vitamin D in her blood due to a never-before-seen mutation which makes her bones particularly prone to breaking (stock image)
The incident was written in the New England Journal of Medicine by researchers from the division of medical genetics at the University of Calgary.
Vitamin D is essential for bone health. Known as the 'sunshine supplement', its main source is UV light, however, it is also found in oily fish, mushrooms and fortified foods.
How vitamin D travels around the body is unclear, however, it was thought to attach to a binding protein that enables it to enter cells.
'The idea has always been that without its binding protein, vitamin D couldn’t get to the cells where it’s needed,' study author Dr Julien Marcadier, a clinical geneticist, said. 'Our findings call that into question.
'To our surprise, she’s maintained normal calcium levels despite having no measurable vitamin D.
'This tells us the vitamin D she has in her system does in fact get to its target cells, though how exactly that happens is still unknown.'
The woman – who does not have children – first came to the doctors' attention when she moved to Canada from her native Lebanon aged 33.
Medics noted she had 'marked' curvature of the spine, as well as poor movement in her back, shoulders and hips.
Her condition became worse over time, despite her taking anti-inflammatory drugs and doing physiotherapy.
The woman also suffered from type 2 diabetes, high blood pressure, elevated lipid levels in her blood, non-alcoholic fatty liver disease, acid reflux and non-cancerous growths of the uterus.
