Lack OF vitamin D trebles the length of time patients stay in hospital, according to new research.
Those with the lowest levels of the sunshine vitamin are also more frail, at higher risk of dementia and falls and are more likely to die in hospital than those with the highest levels.
It is estimated that one in five Britons has low levels of vitamin D (less than 50 nmol/l — or nanomoles per litre of blood).
The vitamin, which helps regulate how the body uses calcium and ensures bones, muscles and teeth are strong, comes mainly from the effect of sunlight on the skin.
Getting enough? Vitamin D helps regulate how the body uses calcium and keeps bones strong
But from October to early March there is not enough sunlight in the UK to give us the vitamin D we need (foods rich in vitamin D such as liver, eggs and oily fish only provide small amounts).
As vitamin D deficiency can contribute to osteoporosis and fractures, the official advice is that children, pregnant women and those who are frail, housebound or in a care home should take a 10mcg daily supplement.
The new findings are based on a review of the health records of 766 patients aged over 65 who were admitted to hospital for problems such as pneumonia, chest or urine infections, falls and confusion over the course of a year.
Vitamin D levels ranged from 14 to 58 nmol/l, with the average being 31 — the cusp of a vitamin D deficiency.
The researchers found that patients with the lowest levels were at greater risk of dementia, had greater nursing needs, double the risk of falls and poorer mobility compared with those with the highest levels.
The study, being presented at the Society for Endocrinology conference in Glasgow this week, also found patients with the lowest levels stayed in hospital on average three times longer than those with the highest — 34 days compared with ten — and were more than twice as likely to die during their hospital stay (32 per cent compared with 14 per cent).
Did you know? A vitamin D deficiency can contribute to osteoporosis and stress fractures
Researchers from the University of Birmingham who carried out the review stress the study does not prove that vitamin D is the cause of these issues.
‘More research is now needed to see if vitamin D plays a role in these outcomes,’ says Dr Zaki Hassan-Smith, a consultant endocrinologist and senior research fellow in Birmingham, and honorary professor at Coventry University, who led the study.
‘One theory is that as vitamin D is involved in muscle function, when it is absent or its effects are blocked it can result in muscle wasting, reducing mobility and potentially increasing hospital stay. It’s also linked to the immune system and could affect the body’s response to infection.’ Simon Pearce, a professor of endocrinology at Newcastle University, said: ‘We know older people who are frail or who have more than one health problem tend to get out of the house less and have poorer diets than healthier people.’
As a result, he adds, ‘it might be expected that these people would have lower vitamin D levels. This large study shows low vitamin D levels are more common in patients who have prolonged hospital stays, those who have dementia and who die in hospital.
‘The important question remains whether improving the vitamin D levels of these people with supplements would lead to improvements in health.’