Written by Colleen M. Story | Published onAugust 5, 2014
Medically Reviewed by George Krucik, MD, MBA on August 5, 2014
Are you getting enough vitamin D? According to recent studies, there’s a good chance you aren’t. In 2009, researchers reported levels of vitamin D in the U.S. population had dropped between the years of 1988 and 1994, and then again between 2001 and 2004. Not only had average levels dropped, more than 75 percent of the people studied had inadequate levels of vitamin D in their blood.
Vitamin D deficiency is linked with an increased risk for serious diseases. Reduced levels of the vitamin are associated with cancer, cardiovascular disease, osteoarthritis, and autoimmune disorders. Deficiency is also linked with multiple sclerosis, type 1 diabetes, depression, and more. That’s why it’s so import to get enough vitamin D. But identifying vitamin D deficiency can be tricky.
Your Lifestyle May Put You At Risk
Our bodies don’t make vitamin D, so we have to get it from our environment. The primary source of vitamin D is the sun, but we can also get it from some foods.
Lifestyle, race, age, and other factors can put you at risk for vitamin D deficiency. If you fit any of the following descriptions, you may need to consider getting more of the vitamin.
You shun the sun. The sun is the primary cause of premature aging on the skin, and it can also increase risk of skin cancer. It’s no surprise, then, that a lot of people try to stay out of it. We’ve all been advised to use sunscreen on a daily basis. While avoiding UV rays can help keep skin healthy and looking young, it can also deprive us of the primary source of vitamin D.
You live in northern latitudes. Those who live in the northern states (north of the 37th parallel) are more at risk of vitamin D deficiency, because of the angle of the sunlight in the winter months. A study published in The Journal of Nutrition concluded that it’s common for people in the northern half of the U.S. and Canada to have insufficient vitamin D in their blood. In the International Journal of Circumpolar Health, researchers also discussed the challenges of vitamin D deficiency in those living in northern latitudes. They determined people in northern latitudes should consider vitamin D supplements in winter months.
You eat a vegan diet. Few foods are good natural sources of vitamin D. The best options are animal foods, such as fatty fish and fish liver oils. Beef liver, cheese, and egg yolks also contain small amounts. If you eat a vegan diet, you’re not consuming these foods, so you may be at greater risk of deficiency. You can eat fortified foods, such as cereals and orange juice, but these may not supply enough on a daily basis.
You have dark skin. The more melanin you have in your skin, the darker it is. Melanin reduces the skin’s ability to make vitamin D from the sun. One study found that African Americans were more at risk of vitamin D deficiency than other Americans. The researchers noted that pigmentation reduces vitamin D production in the skin.
You’re over the age of 65. In The Journal of the American Medical Association, researchers estimated that between 40 and 100 percent of older adults in the U.S. and Europe are vitamin D deficient. They also found that low levels of vitamin D were associated with dementia and other forms of cognitive decline. A Mayo Clinic study also noted that even when seniors get regular sun exposure, their skin produces 75 percent less vitamin D than young adults.
You are obese. A number of studies have linked obesity with vitamin D deficiency. In the Journal of Nutrition, researchers noted that low levels of vitamin D are “highly prevalent” in patients with obesity. A study in The American Journal of Clinical Nutrition, found that vitamin D is less bioavailable in obese people.
You have a digestive disease. People with Crohn’s disease, celiac disease, or other illnesses that affect the digestive tract may experience low vitamin D levels. These diseases can make it difficult for the body to absorb vitamin D from food sources.
You have chronic kidney disease. If you have this disease, you may have more difficulty absorbing and utilizing vitamin D in your body. You may need to take vitamin D supplements.
Symptoms of Vitamin D Deficiency
If you are low in vitamin D, does your body produce symptoms?
The truth is that it’s extremely difficult to tell whether you have a vitamin D deficiency. The only way to be absolutely sure is to take a blood test. Until fairly recently, 20 nanograms per milliliter (ng/mL) of vitamin D in the blood was considered adequate. More recent evidence shows that 30 ng/mL or even 40 ng/mL may be required for optimal health.
Most people with a vitamin D deficiency won’t be aware of it. It doesn’t usually produce noticeable symptoms. However, symptoms are possible. If you are vitamin D deficient, you may experience:
- muscle/joint pain and weakness
- bone pain
- tiredness or fatigue
Examine your risk factors and then check with your doctor. A simple blood test can help you figure out your next steps.
How Is Vitamin D Deficiency Treated?
Standard treatment for a vitamin D deficiency is supplementation. Though it may seem like you could eat the right foods and recover, scientists have found that the level of vitamin D in most foods is too low to correct a deficiency.
Researchers at the Mayo Clinic recommend supplementation with vitamin D3. They suggested a daily dose of 800 to 2,000 IU (international units). The Institute of Medicine sets the daily upper limit at 4,000 IU. If you are taking a vitamin D supplement, always take it with a meal that contains fat for best absorption.
If you’re at risk for deficiency or experiencing any noticeable symptoms, speak with your doctor. They will help determine if you need supplements and the amount that’s right for you.