The recommended daily intake of calcium, which varies with age and gender, is 1,200 milligrams for young adults. But Tordoff points out that around 70 percent of men and 90 percent of women in the United States don’t consume enough calcium.
And the taste of calcium? “Calcium tastes calciumy,” Tordoff said. “There isn’t a better word for it. It is bitter, perhaps even a little sour. But it’s much more because there are actual receptors for calcium, not just bitter or sour compounds.”Tordoff described a delicate balance in the way people respond to calcium in drinking water. “In tap water, it’s fairly pleasant. But at levels much above that, the taste becomes increasingly bad.” Dairy products, such as milk, have a nutritious level of calcium, but Tordoff believes they are special because the calcium in them binds to fats and proteins, which prevents it from being tasted.
High-calcium vegetables include collard greens, bok choy, kale and bitter melon. Tordoff notes a strong correlation between bitterness in certain vegetables and their calcium level, adding that one reason people avoid them, he believes, is because of the taste associated with such high calcium content.
The modification of the sense of taste using genetic research could be an indispensable, widespread tool to increase nutrition, Tordoff said. “I’m not saying people can’t take tablets to get enough calcium, but eating real food is a great pleasure. With salt, sweet and fat, the problem is to reduce intake without reducing palatability. For calcium, it’s a problem of being not palatable enough.”