Conducted by Ipsos for the supplement group Council for Responsible Nutrition (CRN), the survey revealed that 66 percent of American adults classify themselves as supplement users, which is consistent with usage levels over the past few years.
Out of these consumers, 27 percent say they take vitamin D supplements, which marks an increase from 16 percent last year and 16 percent in 2008.
According to CRN, the increased usage figures reflect the growing evidence supporting the benefits of the sunshine vitamin.
“The ever-growing body of research on the benefits of vitamin D has been widely circulated in scientific journals, among healthcare practitioners and within popular press, so it’s no surprise that we are seeing more consumers adding it to their existing supplement routines,” said Judy Blatman, senior VP of communications at CRN.
“Given that optimal levels of vitamin D are difficult to get from diet and adequate sun exposure alone, a vitamin D supplement is the right option for many people.”
Vitamin D refers to two biologically inactive precursors - D3, also known as cholecalciferol, and D2, also known as ergocalciferol. The former is produced in the skin on exposure to UVB radiation (290 to 320 nm). The latter is derived from plants and only enters the body via the diet.
Both D3 and D2 precursors are hydroxylated in the liver and kidneys to form 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.
While our bodies do manufacture vitamin D on exposure to sunshine, the levels in some northern countries are so weak during the winter months that our body makes no vitamin D at all, meaning that dietary supplements and fortified foods are seen by many as the best way to boost intakes of vitamin D.
CRN’s survey results support the findings of an earlier survey published last month, which noted an increased consumer awareness of the vitamin.
Conducted by Angus Reid Strategies for Lallemand, the survey found that the proportion of American consumers that believe that vitamin D plays a great role in maintaining or improving their health increased to 44 percent, up from 37 percent last year.
CRN’s Consumer Survey on Dietary Supplements, which is an annual online survey, was this year conducted between August and September, and involved just under 2,000 American adults.
Other findings include a “fairly consistent” consumer confidence in dietary supplements over the last few years. This year, 82 percent of respondents said they were confident in supplement safety, quality and effectiveness, compared to 84, 81 and 80 percent in 2009, 2008 and 2007 respectively.
The survey also showed that nearly three-quarters of supplement users (74 percent) classify themselves as “regular” users, as opposed to occasional users (21 percent) or seasonal users (5 percent).
In 2009, 73 percent of supplement users indicated they took supplements regularly; in 2008, 75 percent, and in 2007, 77 percent.