In 1892, a British scientist discovered that rickets — a condition causing soft, deformed bones — seemed to be linked to how much sunlight people received. Twenty years later, American researchers found that goats kept inside had far less calcium in their bones than goats allowed outside. Around 1920, two studies in Germany and the U.S. found that ultraviolet light cured cases of rickets in children.
This was the start of the road leading to the discovery of vitamin D. This essential nutrient is the subject of a wave of studies now, from cancer to osteoporosis. But there are so many more, too. Dutch researchers have now found that lower physical performance in older adults may in fact be caused by low levels of vitamin D — not the natural aging process that was assumed.
In the past, we’ve learned that vitamin D deficiency is common as people grow older. This directly leads to bone loss, fractures, and muscle problems. It’s important for older adults to look after their vitamin D status, as they might not get enough sun exposure, not eat enough foods with the vitamin, and possibly lack the ability to make a lot of the nutrient (though we get it from the sun, our liver is responsible for synthesizing it).
The new study involved data on nearly 1,000 adults over 65 years of age. Researchers found that vitamin D was linked strongly to physical performance, even after a handful of other factors were considered. Nearly 50% of the group had low vitamin D levels at the study’s outset, and already they had less physical ability than others. During the following three years, these adults were twice as likely to have declining physical performance. We’re not talking about jogging here, but rather such acts as getting out of a sofa chair.
Vitamin D is a unique vitamin, as we rely on the sun for it because it’s not found to a great extent in foods. As a result, it is a common deficiency to have. But over the past few decades, scientists have started to learn how important it is in preventing disease. Rickets isn’t too common anymore, but serious problems certainly are. And even minor things like getting around on your own steam are tied to this invaluable vitamin.