But how much is enough, and how hard is it to get the right amount of vitamin D?
“We know that a large percentage of the population has suboptimal levels of vitamin D. In fact, as many as half of the U.S. population may be deficient in vitamin D,” said Kristin Gustashaw, clinical dietitian at Rush University Medical Center in Chicago. “This can possibly lead to symptoms including fatigue, tiredness, hair loss, delayed wound healing, decreased immune health, muscle pain, and more, with no other known causes.
“Part of the difficulty of maintaining vitamin D levels is because there are not a large variety of foods that contain much vitamin D,” Gustashaw added in a medical center news release.
The vitamin is accessible to people through some foods, supplements, and even sunshine.
Food sources include egg yolks, milk, cheese, beef or calf liver, and certain fish, such as salmon, mackerel, tuna, and sardines. Other foods are fortified with vitamin D, including certain cereals, breads, soy milk, and orange juice.