VITAMIN D SUPPLEMENT – Do You Need a Vitamin D Supplement?
Vitamin D is known as the “sunshine vitamin” because it’s produced within the body when the sun hits the skin. But many people turn to supplements in cooler months of the year when cold and dark days limit time spent outdoors.
Decreasing vitamin D levels isn’t just a winter issue.
How Much Vitamin D Should You Be Getting?
Adults need 600 international units (IU) of vitamin D each day (800 IU if you’re over age 70), which can be sourced through diet, sunlight, or supplements.
Because very few foods have enough vitamin D to reach those levels, and sunshine can be unreliable in certain climates, many Americans turn to vitamin D supplements to get their fill.
Men and women relying on sourcing vitamin D through diet alone typically don’t exceed 288 IU a day on average. But when supplements are added, they get closer to the 600 IU goal. Consider this: Women between ages 51 and 70, who averaged 156 IU through the diet-only approach, reached 404 IU with the help of supplements.
The Latest Research on Vitamin D Supplements
The problem is that several studies have found that vitamin D supplements don’t live up to the bone-protecting hype.
Research suggests sourcing vitamin D through supplements isn’t beneficial in preventing fractures. And another study found people who took a vitamin D supplement for about two years didn’t have greater bone density or a lower risk of osteoporosis compared with those who didn’t take supplements at all.
Beyond bone health, research also doubts the benefits of vitamin D as a whole. In fact, authors of one review state, “Firm, universal conclusions about its benefits cannot be drawn.”
That said, supplements may be helpful for people who are at high risk of deficiency, such as older people, people with dark skin, people who are obese, and those with limited sun exposure, research suggests.
Why Certain People May Need a Vitamin D Supplement
Why are some groups at greater risk of low vitamin D levels? In most cases, it can be traced back to their diet or lifestyle. Take vegans, for instance.
Many have low vitamin D levels because they avoid foods that are rich in vitamin D — including meat, fish, egg yolks, and dairy products that have been fortified with the vitamin. One study found vitamin D serum concentration was 34 percent lower among study participants who followed a vegan diet compared with those who ate meat and dairy.
People with obesity also may need a supplement. Research suggests the possible reasons for deficiency include a lower dietary intake of vitamin D among obese men compared with non-obese men and women, the possibility that obese people expose less skin to the sun, and a decrease in the absorption rate of vitamin D among people who’ve had bariatri cc or gastric bypass procedures. Indeed, one study suggests recommendations for vitamin D targets should be based on body weight rather than simply suggesting 600 IU for everyone across the board.
As for older people, they’re at risk because they’re more likely to spend time indoors but also because the process of synthesizing vitamin D from food or sunshine becomes less efficient as people age, research suggests.
Finally, people at risk of developing type 2 diabetes should also consider supplements. Low levels of vitamin D have been linked to the onset of diabetes, because the vitamin reduces inflammation and helps regulate insulin release by the body’s pancreatic beta cells, according to one study.
How to Know if You’re Getting Too Much or Not Enough Vitamin D
Concerned your levels of vitamin D are too low? Common symptoms of deficiency include feeling tired and achy, though often there are no symptoms at all. Because that’s vague, the best way to know for sure is by asking your doctor for blood work to assess your vitamin D levels.
What to Know About Vitamin D Toxicity, or Overdosing on Vitamin D
When it comes to vitamin D, more isn’t always better.
Since the vitamin is fat soluble, it’s stored inside the body and can be harmful if your levels get too high. “Too much vitamin D can cause vitamin D toxicity, or hypervitaminosis D,”
You don’t have to worry about overdosing if you rely on your diet and sunlight to reach 600 IU a day. It’s once supplements get added that it becomes a concern. “It’s more common with mega doses of supplements taken over a long period of time — usually doses above 10,000 IU per day,”
Ideally, you never want to exceed 4,000 IU per day, Clifford says. Too much vitamin D can lead to anorexia, weight loss, irregular heartbeats, and excessive urination.
It gets more serious when you end up with excess calcium absorption, which puts your heart, kidneys, and blood vessels at risk.
Symptoms of vitamin D toxicity include:
Loss of appetite
Feeling tired, weak, and confused
Constipation
Frequent urination
Feeling thirsty
