A number of recent studies on vitamin D deficiency published in the last decade fuelled significant sales of vitamin D supplements. Yet, recent reports published in 2010 and 2011 seem to hinder the optimism on vitamin D supplementation based on scientific evidence. Euromonitor International provides insight into the vitamin D controversy.
The miracle vitamin
Vitamin D increased in popularity thanks to the hundreds of recent research studies claiming the extraordinary health benefits of vitamin D to help cure or prevent several diseases. Complicating the controversy, cut-points of sufficiency and deficiency were not consistent among laboratories. A person could have been classified as both sufficient and deficient in vitamin D if the tests were run by two separate laboratories.
The conflicting information on the benefits of vitamin D has led to confusion among the medical community and consumers, who found it difficult to know how much vitamin D they should be taking. Consequently, the governments of the United States and Canada decided to engage in a comprehensive analysis of clinical research studies to gauge the scientific evidence on vitamin D.
The recommended dietary allowance for most people is set at 600 IU/day, while the upper intake level (UL) is 4,000 IU/day. In order to set the revised DRIs, researchers assumed minimal sun exposure to decrease the effect of sun exposure in the daily intake of vitamin D. Consequently, people with more sun exposure obtain a higher dose of vitamin D.
Implications for the future demand of vitamin D supplements
The vitamin D intakes vary greatly depending on the country and population segment. Population living in northern latitudes further away from the equator tend to have lower vitamin D levels as their sun exposure is not sufficient. Alternatively, populations whose main diets include a larger consumption of meat and fatty fish tend to achieve their nutritional daily requirements of vitamin D. The search for a correct balance is not always obvious, but providing safe and reliable information on DRIs can keep populations healthy.
Vitamin D supplements see rising competition from fortified foods and other supplements such as fish oils and multivitamins. The overdose concern remains if a person follows a healthy diet providing enough vitamin D, in combination with a multivitamin and fish oil supplements. For example, if an American woman takes a daily multivitamin (Centrum Ultra Women’s Tablets by Pfizer Inc) providing vitamin D 800 IU, a standard fish oil (cod liver oil by Carlson Labs) with 400 IU vitamin D, and a glass of fortified milk with 115 IU vitamin D, then her minimum daily intake is 1,315 IU, or more than double the recent recommended dietary allowance of 600 IU in the United States.
Moving forward, the recent reports on vitamin D intake will not make single vitamin D supplements disappear from the shelves. People with a medical deficiency and those faithful to the vitamin craze will support future sales. Many people often forget about the nutrients they obtain through their diets (even some fast food have been fortified), and a number of them will continue to purchase vitamin D supplements to “balance” their nutritional requirements.