Vitamin D is an essential nutrient that helps keep bones strong and healthy. It also plays a role in regulating blood sugar levels, helping to prevent cancer, and boosting immunity.
But did you know that vitamin D deficiency is common among people living in northern latitudes? In fact, according to the National Institutes of Health, nearly half of Americans are deficient in vitamin D.
If you live in a cold climate, you might want to consider taking a supplement. However, there’s no evidence that vitamin D supplements effectively prevent osteoporosis or other bone diseases.
So, should you worry about vitamin D deficiency?
The answer depends on your lifestyle and whether you’re concerned about developing osteoporosis. If you’re worried about osteoporosis, talk to your doctor about whether you should take a daily vitamin D supplement.
Importance of vitamin D: Bone health
What does it mean when we say “vitamin D”?
The term “vitamin” comes from vitamins A, C, E, K, B1, B2, niacin, and biotin. German chemist Albert Niemann first isolated these nutrients in 1894. He discovered them while studying beriberi, which was caused by a lack of thiamine in rice. Beriberi became known as Thiamine Deficiency Disease because it affected only those who ate polished white rice without any added thiamine.
In 1900, Dr. John Riggs Williams found that rats fed diets with low amounts of calcium developed rickets — softening of their bones. Then, in 1922, he noticed that milkmaids had fewer cases of this disease than factory workers. This led him to believe that dairy products contained some substance that helped protect against rickets. After isolating what turned out to be vitamin D, he called it “calciferol,” meaning “the source of calcium.”
Today, scientists have identified more than 20 different types of vitamin D. They call one form calcitriol; another forms calciotropic hormones, such as parathyroid hormone and 1,25 dihydroxycholecalciferol.
Calcitriol regulates calcium metabolism throughout the body. When cells need extra calcium, they produce calcitriol. Calcitriol then binds to receptors in various organs, including the kidneys, which stimulates the release of stored calcium into circulation.
Some experts think that calcitriol may play a role in protecting our bodies against many kinds of cancers. For example, calcitriol has been shown to inhibit the growth of breast, prostate, lung, colon, liver, stomach, bladder, ovarian, cervical, endometrial, pancreatic, and skin tumors. Researchers suspect that these anticancer effects occur through mechanisms similar to those responsible for its impact on calcium absorption: increasing intestinal calcium uptake and stimulating kidney tubule resorption of calcium. Other researchers suggest that calcitriol prevents tumor formation by inhibiting cell division. Still, others theorize that calcitriol inhibits angiogenesis, thereby reducing tumor size.
There are two ways to get sufficient vitamin D: sunlight exposure and dietary intake. Most adults can meet their needs simply by spending time outdoors during midday hours. But if you spend most of your daylight hours indoors, as I do, you’ll probably benefit from ingesting foods fortified with vitamin D.
Sources of vitamin D include fatty fish, egg yolk, butterfat, and cod liver oil. And don’t forget mushrooms! Fortified cereals, orange juice, and soy milk are good sources too.
Sources of vitamin D?
Sunlight is not the sole source of vitamin D. It’s also made naturally by bacteria living in the human intestines when we eat food containing prebiotics or probiotics. The best way to consume pre-and probiotic supplements is to make sure they’re combined with healthy fats like olive oils and nuts. You should take at least 5 mg of vitamin D per day. If you want to increase the amount even higher, talk to your doctor about taking an oral supplement.
What happens if you don’t get enough vitamin D?
People whose diet doesn’t contain adequate vitamin D levels often develop bone pain, muscle weakness, and fatigue. Some people experience nausea, vomiting, diarrhea, and constipation. Others might feel depressed or irritable. In extreme cases, severe deficiency causes seizures, coma, and death. Although there is no evidence that eating less sun will prevent cancer, doctors agree that everyone over age 50 should get ten micrograms of supplemental vitamin D each week.
Include vitamin D by adding its sources to your diet!