It is not always possible to say that an endorsement from US TV perennial Oprah Winfrey is backed by cold, scientific logic – the woman is after all an entertainer not a PhD in human molecular nutrition.
But humble vitamin D can rest easy knowing in addition to Oprah’s sales-boosting warm embrace, a growing body of cold, scientific logic is spreading the vitamin D gospel to an ever-widening pool of people becoming aware of vitamin D deficiencies that affect something like 90 of populations in some sun-starved countries.
Once vitamin D, the sun vitamin (the body generates it in the presence of sunlight), was best known for supporting calcium in supporting bone health. Not so anymore. Studies linking the vitamin with muscular support, immune benefits, cancer reduction, insulin response, and gut health have changed the D landscape.
The quality of science has been recognised in the form of positive health claim opinions for immunity and muscular function from the notoriously tough European Food Safety Authority (EFSA), but in terms of dosage levels at least, there is growing frustration that the governing rules are not keeping pace with the science.
The scientific D-bate
Typical recommended daily intakes (RDIs) lie between 200 and 600 international units (IU) per day while more and more science shows the above benefits can be better achieved with levels closer to 2000IU per day without safety concerns.
Some go much higher. One European study found daily doses between 2000-3000IUs could reduce EU health care expenditures by €187bn ($250bn) each year.
Such a situation prompted Frost and Sullivan to observe in a recent report: “Regulatory standards are undoubtedly the primary factor holding back the potential boom of vitamin D market.”
But the situation is at least under review – by both scientific bodies that advise policy makers and by the policy makers themselves.
The influential Institute of Medicine (IOM) in the US is conducting a review of the available vitamin D science and is due to deliver its findings this summer. Many expect the IOM to recommend RDIs much above the current levels of 400IU. Oprah has been telling her viewers the RDI should be 2000IU or more.
The IOM may also revise upper safe levels (USLs) with some saying 10,000IU per day reflects the scientific literature – this would be a great boon to supplement manufacturers seeking to meet demand for high-dose products.
However such high-dose practises may be under threat in the European Union as USLs are due for resolution as part of the Food Supplements Directive soon, and they may come in much lower than many are hoping for.
In Europe just this week, the European Parliament hosted a conference where European vitamin D deficiencies were highlighted and issues like the establishment of USLs touched on.
Irish Member of European Parliament Jim Higgins came away from the meeting stating: “The statistics given by the expert panel, together with the range of diseases caused by Vitamin D deficiency illustrate that there is a huge amount of work to be done in terms of bridging the public awareness of the importance of the nutritional value of Vitamin D.”
Such awareness has been done no harm by EFSA’s recent positive vitamin D health claim opinions that are likely to be written into the EU law books at some point this year, and on products soon after. Those opinions can be found here.
While vitamin D’s ability to benefit cardiovascular health was not backed by EFSA, DSM Nutritional Products’ senior marketing manager in human nutrition and health, Wouter Claerhout, said clinical trials in this area would provide interesting new data in the heart area.
“It’s only a matter of time,” he said.
High dose D
So there remains regularity ambiguity, and that is mimicked in most places outside of the EU and North America, but high-dose products are finding their way to market regardless.
“We are seeing 1000 IU and 2000 IU products, which do give consumers dosing flexibility,” said Samantha Chmelik, industry manager of consumer health at Euromonitor International.
Paul Chamberlain, the technical manager at dietary supplements manufacturer, Solgar UK, said his company had been producing a 2200IU version since 2009 that was selling very well along with lower dose vitamin D products.
“Vitamin D has been booming for several years with all the media attention,” he said noting Solgar products made no on-pack health claims. “Especially the immune science has captured the imagination of people.”
Mandatory fortification is in place in isolation with the likes of the US, Finland and Sweden fortifying milk, but typically at very low levels.
A vitamin D fact sheet produced by the US Office of Dietary Supplements can be found here.
To access the first part in this vitamin D series, click here. On Monday, Jane Byrne will look into formulation challenges surrounding vitamin D.