NYU professor questions supplements; vitamin D expert supports efficacy of oral forms

Does vitamin D belong on the Nutrition Facts panel?

Does vitamin D belong on the Nutrition Facts panel?

FDA proposals to list "added sugars" on the Nutrition Facts panel have already generated heated debate, so it's unsurprising that its plan to include vitamin D is proving equally controversial, with critics claiming it could encourage over-consumption and "junk food fortification" and supporters claiming oral ingestion is an effective way to boost low levels in the US population without the side effects of sun exposure.

The proposal in question involves removing vitamins C and A as mandatory micronutrients and requiring manufacturers to declare Vitamin D and potassium, which are now considered “nutrients of public health significance” along with calcium, based on the 2010 Roadmap to the Dietary Guidelines (read more on the proposed changes here). Marion Nestle, PhD, New York University, took issue with voluntarily adding vitamin D to labels, raising questions about its status as a vitamin and its efficacy when consumed orally.

“’Vitamin’ D is not a vitamin; it is a hormone synthesized by the action of sunlight on skin,” she wrote last week on her blog Food Politics. “For this reason alone, it does not belong on the food label.”

Speaking with FoodNavigator-USA a few days after posting the blog entry, Dr. Nestle said she suspects that proponents of vitamin D supplementation likely pushed to get it added to labels, claiming that using 25-hydroxyvitamin D criterion to measure deficiency is suspect.

“Making the active hormone is a multi-step process, beginning with sunlight on skin,” she said. “It is so much more efficient to obtain the hormone from the action of sunlight on skin and it doesn’t take much skin exposure to meet requirements [15 or 20 minutes produces the equivalent of taking 20,000 IU orally]. Supplements bypass the regulatory controls of the hormone, which is made as needed and stored, or not made if there’s already too much.”

Vitamin D expert Michael Holick, MD, PhD, Boston University Medical Center, said that while he’s “all for sunlight”, he also recognizes the efficacy of orally administered vitamin D—with without the side effects of UV exposure—which is supported by numerous studies (see here, here and here).

“We know a lot about oral vitamin D from a multitude of studies,” he said. “We know that the vitamin D you get from the diet and or fortifying foods is metabolized identically as when you are exposed to sunlight.”

Form, dosage of vitamin D still contested; FDA hasn’t addressed bioactivity of D2, D3

Vitamin D refers to two biologically inactive precursors, D3 and D2. D3, also known as cholescalciferol, is produced in the skin on exposure to UVB radiation. D2, also known as ergocalciferol, is derived from plants and only enters the body through the diet. Both D3 and D2 precursors are transformed in the liver and kidneys into 25-hydroxyvitamin D, the non-active “storage” form, and 1,25-dihydroxyvitamin D, the biologically active form that is tightly controlled.

Many researchers agree that many people are vitamin D deficient and need vitamin D supplements, but the form and recommended dose are still up for debate. Indeed, in recent comments to the FDA on its Nutrition Facts proposals, the Council of Responsible Nutrition called on the agency to take a stance on D2 and D3 by either defining them as bioequivalent or “listing a potency conversion factor if, in fact, the agency considers one form more bioactive than the other.”  

Per the Institute of Medicine (which Dr. Holick referenced), serum 25hydroxyvitamin D of 20 nanograms per milliliter are necessary for good bone health. According to the Endocrine Society, between 21 and 29 ng/ml is considered an insufficiency, and 30 and above sufficient in order to maximize bone health and take advantage of the benefits of vitamin D.

Will more fortification lead to overconsumption?

Because the hormone vitamin D is naturally found in very few foods, it’s present in most foods as a result of fortification. Dr. Nestle said that permitting vitamin D disclosure on food labels will likely encourage fortification of foods that may not otherwise be recommended, providing the example of Yum Bunny Caramel Milk Spread, a spread fortified with vitamin D at 10% of the DV that’s “clearly aimed at children” on her blog.

The potential for more vitamin D in the food supply also raises questions about overconsumption and toxicity, as vitamin D is a fat-soluble hormone stored for long periods in body fat, she said. Indeed, the IOM said it is concerned about the possibility of adverse consequences from overconsumption through supplementation or fortification.

But Dr. Holick noted that as long as manufacturers put the amounts they say they are in products, overconsumption isn’t a concern for children or adults. “The IOM says the upper limit in children over 1 is 2,500 units a day and 4,000 a day in adults—but up to 10,000 units is perfectly safe,” he said. “Even if you drink a gallon of milk or fortified orange juice, you couldn’t get anywhere close to those ranges.” 

Related News

CRN, NPA submit comments on FDA's proposed changes to food, supplement labels

CRN, NPA submit comments on FDA's proposed changes to food, supplement labels

Research supports ever-wider role for vitamin D, CRN says

Research supports ever-wider role for vitamin D, CRN says

Higher calcium and vitamin D fortification levels present big technical challenges in juice, claims the Juice Products Association

Juice Products Association: Nutrition Facts overhaul could spell end to vitamin D and calcium fortified juices

FDA's current and proposed Nutrition Facts updates, protein content, declared protein, folate, folic acid, added sugar

AHPA to FDA: Clarify protein labeling

Out with the old... Proposed changes to the Nutrition Facts panel would make serving sizes more realistic, highlight added sugars, and make calories much more prominent

Changes to Nutrition Facts panel may have limited impact on consumer perceptions, says Hartman Group

American Diabetes Association: 'While it is true that naturally occurring sugars and added sugars have the same physiological impact, the difference is significant when considering dietary quality'

Should ‘added sugars' be listed on the Nutrition Facts panel?

Professor Kessler: 'To the harried shopper hoping to make some healthy choices, this label would offer a quick way of identifying high-calorie, obesity-inducing food'

Former FDA commissioner: Nutrition Facts overhaul doesn’t go far enough

GOED 'respectfully disagrees' with the FDA over its assessment of the evidence supporting the benefits of EPA and DHA

Nutrition Facts overhaul is a missed opportunity for long chain omega-3s EPA and DHA, says GOED

Comments (4)

Gary Ewdards - 08 Aug 2014 | 12:53

Vit D and Maize

Vitamin D is available without any maize via bakers yeast grown in the presence of UV light....this can then be used as a supplement in pure form or used to make baked goods with levels high enough to even achieve "excellent source" claims. The old idea that D in your diet is only in oily fish and milk is outdated.

08-Aug-2014 at 00:53 GMT

Anna Jacobs - 07 Aug 2014 | 09:54

Vit D and maize

I'd be happy if manufacturers would start making Vit D without maize/modified starch as a filler. It' hugely difficult to find any Vit D that doesn't contain it!

07-Aug-2014 at 09:54 GMT

Submit a comment

Your comment has been saved

Post a comment

Please note that any information that you supply is protected by our Privacy and Cookie Policy. Access to all documents and request for further information are available to all users at no costs, In order to provide you with this free service, William Reed Business Media SAS does share your information with companies that have content on this site. When you access a document or request further information from this site, your information maybe shared with the owners of that document or information.