Vitamin D helps regulate the amount of calcium and phosphate in the body, nutrients that are needed to keep bones, teeth and muscles healthy.
It is well understood that lacking the sunshine vitamin can lead to bone deformities, such as rickets in children, and bone pain caused by a condition called osteomalacia in adults.
In addition to bone problems, new research suggests a vitamin D deficiency can also disrupt muscle function.
Research published in the international journal Clinical Interventions in Ageing, shows that vitamin D deficiency is an important determinant of poor skeletal muscle function in adults aged 60 years and over.
The findings are based on the analysis of data from 4157 community-dwelling adults aged 60 years and over, from the English Longitudinal Study of Aging (ELSA).
While resistance exercise is known to preserve and enhance muscle function, the new study suggests that adequate vitamin D status may also be protective.
The study found that muscle weakness was twice as high among among older adults with vitamin D deficiency compared with those who had healthy vitamin D levels.
READ MORE: Vitamin D warning: Pain in this area of the body may mean you’ve had too many supplements
How to treat a vitamin D deficiency
From about late March/early April to the end of September, most people should be able to get all the vitamin D they need from sunlight.
However, during the autumn and winter, you need to get vitamin D from your diet because the sun isn’t strong enough for the body to make vitamin D.
According to the NHS, vitamin D is also found in a small number of foods, including:
- Oily fish – such as salmon, sardines, herring and mackerel
- Red meat
- Liver
- Egg yolks
- Fortified foods – such as most fat spreads and some breakfast cereals
In some countries, cows’ milk is fortified with vitamin D but in the UK, cows’ milk is generally not a good source of vitamin D because it isn’t fortified, explains the NHS.
Another source of vitamin D is dietary supplements, which you can most pharmacies and supermarkets.
According to the NHS, if you choose to take vitamin D supplements, 10 micrograms a day will be enough for most people.
“Taking too many vitamin D supplements over a long period of time can cause too much calcium to build up in the body (hypercalcaemia),” warns the health body.
People with certain medical conditions may be recommended to consult their doctor before taking vitamin D supplements, however.
“If your doctor has recommended you take a different amount of vitamin D, you should follow their advice,” says the NHS.
Other risk factors associated with a vitamin D deficiency
Some people are particularly at risk of a vitamin D deficiency.
According to The Department of Health recommends that you take a daily supplement containing 10 micrograms of vitamin D throughout the year if you:
- Aren’t often outdoors – for example, if you’re frail or housebound
- Are in an institution like a care home
- Usually wear clothes that cover up most of your skin when outdoors
“If you have dark skin – for example you have an African, African-Caribbean or south Asian background – you may also not get enough vitamin D from sunlight,” adds the health body.