Daily vitamin C supplements could be as effective as walking in improving the heart health of obese people, a study claims.

Those adults who are overweight and obese are advised to take regular exercise to help improve their health.

But, more than 50 per cent do not fulfil the recommendation.

Scientists have now suggested that taking vitamin C supplements each day - the equivalent to one Berocca tablet - can have similar cardiovascular benefits as regular exercise.

The blood vessels of people who are overweight or obese show elevated activity of the small vessel-constricting protein, endothelin (ET)-1.

Those vessels with high ET-1 activity are more prone to constricting.

This narrowing of the blood vessels can mean blood vessels are less responsive to the changing demands on blood flow, therefore increasing a person's risk of vascular disease.

Past studies have found exercise helps to reduce ET-1 activity.

But many overweight or obese people use a lack of time as an excuse for not incorporating exercise into their daily routines.

In this study, scientists at the University of Colorado examined whether vitamin C supplements, which have been found in the past to improve vessel function, can also lower ET-1 activity.

Their findings, which will be presented at the 14th International Conference on Endothelin: Physiology, Pathophysiology and Therapeutics, suggest the supplement can have similar benefits to a person's heart health as exercise.

The analysed 35 sedentary, overweight or obese adults over a period of three months.

Twenty of the participants took daily supplements, while 15 undertook daily aerobic exercise training. 

Scientists measured their forearm blood flow, as well as responses to intra-arterial infusion of ET-1 before and after each intervention. 

Researchers found that daily doses of vitamin C - 500mg a day, released over the day - reduced ET-1 related vessel constriction as much as walking did. 

They also found vaso-constriction - the narrowing of blood vessels - in response to ET-1 increased similarly - about two-fold - in response to both interventions.

As a result, the team concluded that vitamin C supplementation represents an effective lifestyle strategy to reduce ET-1 mediated vessel constriction in overweight and obese adults.

The NHS recommends adults need 40mg of vitamin C each day, adding 'you should be able to get all the vitamin C you need from your daily diet'.

There is roughly around 45mg of vitamin C in an average orange, while a single Berocca tablet contains 476mg of the nutrient.

However taking too much of the nutrient - more than 1,000 mg - a day can cause stomach pain, diarrhoea and wind.

The NHS adds: 'Taking less than 1,000 mg of vitamin C supplements is unlikely to cause any harm.'

Meanwhile in the US, the National Institutes of Health advises adult men need 90mg a day, while adult women need 75mg daily.

The NIH warns: 'Taking too much vitamin C can cause diarrhoea, nausea and stomach cramps.'

It advises adults should take no more than 2,000mg of the nutrient each day.