If you live in North America, chances are good you don't get enough vitamin D. And when food companies want to focus on products that enhance bone health, incorporating vitamin D is a good way to do it. About 42 percent of Americans are deficient in vitamin D, according to the journal Nutrition Research. That's a big percentage, and also why vitamin D is being added to the updated Nutrition Facts Panel listing requirements.
A vitamin D deficiency can harm health in ways we may not expect. Symptoms of vitamin D deficiency include bone pain, muscle weakness, higher blood pressure and depression.
Innova Market Insights (www.innovadatabase.com) says the market for bone and joint health food products still remains very niche, as product launches it tracked with either a bone or joint health claim represent under 1 percent of all global food and beverage launches in 2014 and again in 2015.
With few natural food sources of vitamin D, processors can fortify foods with vitamin D to help consumers meet recommended daily intakes. Vitamin D supports calcium metabolism, and both of these nutrients are critical for bone health throughout life. Calcium is essential to bone remodeling (over time, bones can develop cracks), explains Robert Gagel, director of the Bone Disease program at the University of Texas and immediate past president of the National Osteoporosis Foundation (NOF).
In addition to its role in bone health, vitamin D helps with cognitive impairment, asthma, cancer and the risk of cardiovascular disease. As a hormone, vitamin D helps raise calcium in the bloodstream by increasing the body's ability to absorb calcium from foods and by reducing the amount of calcium lost in urine. As a last resort, it will boost calcium in the bloodstream by pulling calcium from the bone to support blood levels. And that's not always a good thing.
Greatest sources are fortified
While fish is a good source for vitamin D, fish consumption remains low in the U.S., making eggs and dairy foods favorable dietary alternatives to help increase vitamin D consumption, according to the American Egg Board (www.aeb.org). With that nutrient concentrated in the yolk, one large egg (50g) contributes 41 IU of vitamin D.
Certain mushroom species, including shiitakes, contain as much as 5 percent vitamin D, says the American Society of Nutrition in its Advances in Nutrition journal. "Mushrooms stand out in the produce aisle as a source of vitamin D and one of the few non-fortified food sources," notes the Mushroom Council (www.mushroominfo.com), Redwood Shores, Calif. In fact, the Institute of Medicine recognizes mushroom as the exception to the rule that plant foods don’t naturally contain vitamin D.
Yet the greatest food sources of vitamin D aren't whole, natural foods, but processed foods that are fortified, and food companies receive requests for fortification across a broad spectrum of products. Dairy-based, calcium-rich beverages such as milk are popular for strengthening bones, and like most foods, milk doesn't naturally contain vitamin D. Still, the majority of consumers consider vitamin and mineral content milk's most important attributes, Mintel (www.mintel.com) says. Bone health and taste are leading reasons why people drink dairy milk, the market research firm points out. However, Mintel also says dairy milk sales are still declining in favor of non-dairy milks, flavored, organic and lactose-free versions, which are seeing significant growth.
Providing milk-equivalent quantities of bioavailable calcium, Switzerland's Omya International AG (www.omya.com) offers Calcipur natural calcium carbonates (about 40 percent) for the fortification of vegan based on soy, rice, oat, coconut or almond drinks as well as products like snacks, breakfast cereals and baked goods. The concentrated powdered calcium works with various viscosities, says Tanja Budde, head of Omya's innovation and technical marketing. Budde says different particle sizes are available to ensure stability and a low sedimentation rate.
"The growing desire for vegan options is a current driver [for bioavailable calcium]," explains Stefan Lander, vice president consumer goods at Omya. "Many consumers now eschew cow milk products because of ethical or intolerance reasons, but don’t want to miss out on their nutritional benefits. We help develop non-dairy drinks that combine indulgence with a highly valuable nutritional profile."
Building bone density
Vitamin D supplementation is available in two types: vitamin D2, also called ergocalciferol, and vitamin D3, also known as cholecalciferol — both of which are good for bone health, the NOF says. Beverages like juice drinks are supplemented with calcium and vitamin D3, and soy-based beverages and soy products with vitamin D2.
Supplying most of the vitamin D in the diet, dairy products like yogurt and low-fat cheese are rich in bone-building calcium and are often fortified with vitamin D. It turns out that the vitamin isn't found in all yogurt. Even within a particular brand of yogurt, some products may have vitamin D while others don't.
Scientists previously looked at the connection between vitamin C and bone development, but were unsure whether or not it would help increase bone density. Now, researchers say the vitamin C in orange juice actually can boost bone density and produces collagen, a substance that forms the body's connective tissues. Fortified orange juice, such as Coca-Cola's Minute Maid Pure Squeeze orange juice with calcium and vitamin D, can have as much calcium as a glass of milk.