A new Tufts Universitystudy involving more than 27,000 Americans is the latest research to show that most supplements may not do much to improve health - or at least can't compete with the benefits of a healthy diet.
"But, we need more research to look at long-term use of supplements".
The objective of the study was stated to be to "evaluate the association among dietary supplement use, levels of nutrient intake from foods and supplements, and mortality among U.S adults".
This was associated with a 53 per cent greater risk of death from cancer, although the relative risk remained small.
Professor Judy Buttriss, of the British Nutrition Foundation, said the findings added to a growing body of evidence that micronutrient supplements do not reduce the risk of death. After that, a household interview was held, and they had to answer whether or not they had used any vitamin supplements in the previous 30 days.
Nutrient intake from foods was also assessed using 24-hour diet recalls conducted by trained interviewers.
The scientists compared the intake of a range of nutrients with rates of death from all causes, cardiovascular disease, and cancer.
The researchers found that taking supplements didn't lower the risk of death during the study follow-up period, while those who got the recommended amount of certain nutrients from foods had a lower risk of death in that time frame. "So we should go with what the dietary recommendations suggest to achieve adequate nutrition from food, rather than relying on supplements", he said.
The study used data from more than 27,000 United States adults ages 20 and older to evaluate the association between dietary supplement use and death from all causes, cardiovascular disease (CVD), and cancer. They found that insufficient intakes of magnesium and vitamin K were associated with lower risk of death.
When sources of nutrient intake were evaluated, the researchers found that lower risk of death associated with adequate nutrient intakes was limited to nutrients from foods, not from supplements. But after they adjusted for factors like education, socioeconomic status and demographics, it became apparent that mostly higher-income, better-educated people - who are more likely to be in good health to begin with - were taking supplements.
They showed that adequate consumption of vitamins A and K, as well as magnesium and zinc, reduced the risk of death.
'Furthermore, there are those who eat poor quality diets but take a supplement as an insurance policy.
The study analysed the association between nutrient intake and risk of death. The academy points out that foods can contain beneficial components that aren't found supplements, such as fiber or bioactive compounds.