Global disparities for vitamin C recommendations raise questions over deficiencies

11 Aug 2022 --- The International Alliance of Dietary Supplement Associations (IADSA) is calling for a global agreement on vitamin C recommendations as figures between the lowest and the highest have a near-threefold difference.

Vitamin C prevents scurvy, a disease that was once common among sailors but is now rare. However, it also performs a number of important functions in the body. In particular, it helps protect cells from oxidative damage and helps to maintain healthy skin, bones and cartilage. It also supports the immune and nervous systems.

“Some governments are basing their recommendations on the prevention of deficiency, others are looking at adequate levels, and some have now set higher recommendations in order to decrease non-communicable disease,” Cynthia Rousselot, IADSA director of technical and regulatory affairs, tells NutritionInsight.

This approach is not unique to vitamin C and is also the case for other nutrients, she explains. The UK earlier this year announced an inquiry to tackle vitamin D deficiencies. 

Studies indicate that elderly people may have a lower vitamin C status.Wide-ranging figures
The varying recommendations between recommended daily allowance (RDA) figures and nutrient reference values (NRV) are surprising, according to IADSA, as the scientific data underlying the recommendations are broadly the same.

For instance, the European Union’s recommended daily allowance of vitamin C for men is 110 mg per day and 95 mg for women. In the UK and India, the figures are slashed by more than half at 40 mg per day for both men and women. 

In some countries, the RDA/NRV is greater for men than women, who tend to have a higher vitamin C status. In addition, there are higher RDAs/NRVs for certain population groups. Many countries now recommend an additional 10 to 20 mg per day for pregnant women. If they’re lactating, those recommendations increase to an additional 20 to 60 mg per day, IADSA explains.

“The impact (of not having global guidelines) really depends on the nutrition policies of countries. Clearly, if a government moves towards an approach based on optimal health, they will be seeking to ensure their population receives the levels of nutrients to achieve this,” notes Rousselot. 

Upping intake
Some countries set higher RDAs/NRVs for smokers, as smoking has been shown to increase oxidative stress and cause the body to use vitamin C at a faster rate. 

In Austria, Germany and Switzerland, smokers are encouraged to consume 155 mg of vitamin C a day if they are male and 135 mg if they are female.

Additionally, IADSA cites research which notes people with higher body weight are more likely to have lower vitamin C status.

“The benefits of vitamin C stretch well beyond the prevention of scurvy into a range of other key areas of health and well-being,” states Dr. Gerhard Gans, chair of IADSA. 

“To optimize people’s vitamin C status, IADSA believes that greater consideration needs to be given to the setting of appropriate daily intake recommendations. We agree that aligning the criteria used for establishing these would be a positive step.”

Demand for vitamin C has seen an increase with the onset of the COVID-19 pandemic, leading to an “arms race” of competition between companies as consumers sought out products for their health and immunity. 

By Andria Kades