Are You Vitamin D Deficient? (And How to Fix It)

We all know Vitamin D as the so-called Sunshine Vitamin. It gets its nickname because one of the best natural sources of Vitamin D is direct exposure to sunlight.

What you may not know is that Vitamin D deficiency is one of the most common vitamin deficiencies in the world. Not getting enough of this important micronutrient can interfere with your health in a variety of ways.

How do you know if you’re deficient in Vitamin D? What can you do about it? Here’s what you need to know.

vitamin d deficiency

What Does Vitamin D Do?

Let’s start by talking about the role Vitamin D plays in the human body. Like most micronutrients, it does several things. For example:

  • Vitamin D plays a key role in your body’s absorption of calcium. As you probably know, calcium is what our bones are made of. Vitamin D helps keep your bones dense and strong.
  • Vitamin D also regulates the neuromuscular system – your body’s ability to use your muscles and the nervous system’s ability to send signals throughout your body.
  • Vitamin D is essential for a strong immune system. The immune system protects you from disease and infection.
  • Finally, Vitamin D is important for the life cycles of every cell in your body.

You can see why Vitamin D is considered an essential micronutrient.

It may interest you to know that our bodies make Vitamin D. However, we need to get enough sunlight to be able to do so. Approximately 42% of all people in the United States are deficient in Vitamin D.

How Much Vitamin D Do We Need?

How much Vitamin D do you need to be healthy? That’s an important question and one that everybody should know.

According to the Institute for Medicine, the recommended daily allowance (RDA) of Vitamin D is 600 IU (international units.) However, some experts say that more is necessary. For example, the Endocrine Society recommends between 1,500 and 2,000 IU per day. The Mayo Clinic considers the minimum to be 600 IU but says that getting 1,000 to 2,000 IU per day is safe.

vitamin d dosage

There are some health conditions where taking additional Vitamin D may be desirable. For example, there’s some research to suggest a link between breast cancer and Vitamin D deficiency. Some experts recommend that women take a high dose of Vitamin D to prevent breast cancer.

What Causes Vitamin D Deficiency?

A Vitamin D deficiency is caused by not getting enough Vitamin D – or, in some cases, not getting enough sunshine for your body to manufacture the Vitamin D it needs.

For most people, being exposed to direct sunlight for 15 minutes three times a week will provide all the Vitamin D they need. However, there are some risks associated with sun exposure – and some mitigating factors as well.

You may already know that staying in the sun for too long can increase your risk of skin cancers such as melanoma.

There are also some genetic, health, and geographical factors that can impact how much Vitamin D you have. For example:

  • People with dark skin absorb less sunlight than those with light skin, which means that Vitamin D deficiency is more likely to impact people of color.
  • People who have kidney disease may be deficient because their kidneys can’t properly convert Vitamin D to its active (usable) form.
  • People with Celiac disease, Crohn’s disease, and cystic fibrosis may not be able to absorb Vitamin D in their intestines.
  • People who are obese may have low Vitamin D because their fat cells absorb Vitamin D from the bloodstream.
  • People who live far from the equator get less Vitamin D, on average, than people who live close to it. That’s because the sun is at an angle that minimizes exposure the closer you get to the poles.
  • Living in a place with fewer daylight hours – or few sunny days, like the Pacific Northwest – can lead to a deficiency.

Finally, if you don’t get enough sun exposure and don’t eat foods that are fortified with Vitamin D, you may have a deficiency.

What Are the Symptoms of Vitamin D Deficiency?

It can be difficult to tell if you have a Vitamin D deficiency, but here are some symptoms you should know about:

  1. You get sick frequently. Vitamin D is important for your immune system. If you’re deficient, you may be susceptible to viruses and infections as a result.
  2. You’re tired or fatigued. People who lack Vitamin D often feel listless and tired. They lack energy to do everyday things.
  3. Your bones hurt. Because Vitamin D plays a key role in maintaining healthy bones, people who don’t get enough Vitamin D may experience backaches and other bone-related symptoms.
  4. Wounds don’t heal quickly. People who don’t get enough Vitamin D sometimes notice that cuts and scrapes don’t heal quickly.
  5. You feel depressed. Vitamin D plays a role in mood regulation. People who don’t get enough sometimes feel depressed, anxious, or sad.
  6. You’re losing hair. Hair loss can be caused by many things, including genetic factors. However, some people who lack Vitamin D can lose hair as a result.
  7. You’re losing bone mass. People who are deficient in Vitamin D are at a higher risk for osteoporosis than people who get enough.
  8. Your muscles hurt. One study found that 71% of people with chronic muscle pain had a Vitamin D deficiency.

If you’ve experienced any of these symptoms, it’s possible you have a deficiency of Vitamin D.

vitamin d symptoms

Health Risks Associated with Vitamin D Deficiency

There are some significant health risks associated with Vitamin D deficiency. Here are some to be aware of:

  • As we mentioned earlier, Vitamin D deficiency can increase your risk of osteoporosis
  • There’s some evidence that Vitamin D deficiency increases the risk of breast cancer
  • Deficiency may also increase your risk of cardiovascular disease.
  • Children who are deficient in Vitamin D are more likely to have asthma.
  • In addition to breast cancer, Vitamin D deficiency may increase your risk of other kinds of cancer
  • Vitamin D deficiency has been linked to cognitive impairment in older adults

These are significant health risks. They illustrate why it’s essential to get enough Vitamin D every day.

The Sources of Vitamin D

You already know that your body can make Vitamin D after exposure to direct sunlight. However, sunlight is not the only source of Vitamin D. There are only a few natural dietary sources, but some foods are fortified with Vitamin D.

Natural sources of Vitamin D include:

  • Fatty fishes such as tuna, mackerel, and salmon
  • Egg yolks
  • Beef liver
  • Cheese

You can also find Vitamin D in some manufactured foods that are fortified with it. These include:

  • Milk and other dairy products
  • Breakfast cereals
  • Orange juice
  • Soymilk and other milk substitutes

Many foods that are fortified with Vitamin D say so on the packaging. For example, if you stroll down the cereal aisle of your local supermarket, you’ll see many brands touting the vitamin content – and that includes fortification with Vitamin D.

Vitamin D Sources

How to Reverse a Vitamin D Deficiency

So, what’s the best way to reverse a Vitamin D deficiency? Here are some tips to help you.

  1. Get out in the sun. Put on sunscreen and spend 20-30 minutes in the sun every day. For ideal results, you should have at least 40% of your body exposed to the sun.
  2. Eat foods that are rich in Vitamin D.
  3. Take a Vitamin D supplement. Most experts suggest a Vitamin D3 supplement since Vitamin D2 has not been shown to be effective at reversing a deficiency.

People who live in northern climates or who have a deficiency in the winter should take a supplement. To reverse a deficiency, it may be necessary to take as much as 6,000 IU per day.

For a very serious Vitamin D deficiency, some experts recommend a shot of 50,000 IU of Vitamin D once a week for a total of eight weeks. Children between the ages of one and 18 can take 2,000 IU a day, while adults should take 6,000 IU a day.

If you do decide to take a Vitamin D supplement, make sure to take it with food that contains some healthy fat. Vitamin D is a fat soluble vitamin and your body will be better able to use it if you take it with some fat.

If your doctor determines you have a Vitamin D deficiency, you’ll need to be tested after eight weeks until you achieve a blood level of 25(OH)D and about 30 ng/mL. Once you’re at that level, you’ll need to continue with maintenance therapy. (600-1,000 IU per day for children and 1,500-2000 IU per day for adults.)


Vitamin D deficiency is very common and can be detrimental to your health. If you think you may be deficient, ask your doctor for a test and follow their instructions to reverse the deficiency and maintain healthy levels of Vitamin D going forward.