Are you feeling tired, achy, and just not yourself lately? If so, it’s possible that you’re suffering from a vitamin D deficiency—something which is more common than you might think. Statistically speaking, it’s estimated that about 1 billion people worldwide have a vitamin D deficiency. And here in the U.S., more than 1/3 of adults are vitamin D deficient. But it’s not just adults. This study advises that 50% of children ages 1 to 5 and close to ¾ of those ages 6 to 11 have a vitamin D deficiency.

BLOG: Vitamin D Deficiency and Mortality

What exactly is a vitamin D deficiency? As this article puts it, a vitamin D deficiency quite simply means that you don’t have enough vitamin D in your body. The same is true if you have a vitamin D insufficiency. Some global stats show that ½ of the population is vitamin D insufficient. Not having enough vitamin D in your system is a big enough problem that the Dietary Guidelines for Americans, the government’s gold standard recommendations for nutritional advice, calls out the lack of vitamin D as a public health concern.

What defines deficiencies in terms of vitamin D levels? We’ll get to that later in this blog.


What is Vitamin D and Why do we Need It?

Vitamin D is one of the key vitamins that you need for growth and overall good health. For starters, it helps build strong bones and teeth. More recently, vitamin D has been touted as a strong supporter of your immune system, in part because of its anti-inflammatory properties.

Additionally, there’s a growing body of research—some well-established and some emerging—that supports the need for getting enough vitamin D in your body to support your metabolic function, your heart health, your cognitive function, your mood (it’s not called “the sunshine vitamin” for nothing!), as well as your body’s muscles.

BLOG:  How Does Vitamin D Affect Your Heart?

Vitamin D may also play a role in reducing the risk of some cancers, help reduce the risk of postpartum depression, aid in regulating insulin and blood sugar levels and help combat fatigue.

But don’t throw away your other healthy habits, or other vitamins, as while vitamin D may be a superstar, it’s also a team player, relying on cooperation with other vitamins and minerals as well as a proper diet and regular exercise for you to benefit from its best performance.

There are some people who are more likely than others to be vitamin deficient or insufficient. Here are just some examples of those people who are more at risk,  especially if they’re not supplementing with vitamin D:

  • older people
  • pregnant women
  • postmenopausal women
  • people with darker skin
  • vegetarians or vegans
  • those who practice (the good practice of) using sunscreen protection
  • those who live in climates where the sun is less likely to show its face
  • those who live in geographical locations with high pollution
  • people with certain medical conditions
  • people who take certain medications

Let’s drill down on some of those situations that might lead to a vitamin D deficiency.


You Can’t Count on the Sun Alone

Sun exposure used to be considered the best way to get your vitamin D. That’s because when the sun’s rays beat down on you, your body manufactures its own vitamin D. More specifically, it’s the ultraviolet B rays (UVB) that interact with a protein in your skin (known scientifically as 7-DHC) that converts that protein into vitamin D3.

It could take only about 5 minutes without sunscreen (depending on skin pigmentation, season and more) of unfiltered and unprotected sun exposure per day to help your body manufacture about 200 IU of vitamin D. However, it’s the word “unprotected” that is the problem. As skin cancer became more prevalent, doctors recommended less exposure to the sunlight and proper attention to using high SPF sun protection. Both of these reduce the sun’s ability to help you generate vitamin D but could potentially prevent skin cancer.

BLOGL Does Vitamin D Deficiency Cause Bruising?

That doesn’t mean you should sit inside all day. You need fresh air. And you need some exposure to sunlight. It means that you should smartly use sun protection. Don’t bake in the sun as was the common practice in the 60s and 70s (who else remembers slathering on baby oil?).

But even if everyone wanted to take a daily walk to help their body make its own vitamin D, there are air pollution problems that interfere with that benefit and climates that do the same. As this article explains, accompanied by a nifty map for those living in America, “except during the summer months, the skin makes little if any vitamin D from the sun at latitudes above 37 degrees north or below 37 degrees south of the equator.” This means that people in places like Boston, Denver and San Francisco, as well as Buenos Aires and Canberra, are just a small number of the places that can’t count on the sun for all of their vitamin D needs.


Medical Conditions and Medications That Prevent Vitamin D Absorption

Other people at a higher risk for vitamin D deficiency include those with the following medical conditions:

  • Obesity—this article says that a body mass index above 30 is associated with lower vitamin D levels. Your body stores vitamin D in fat tissues and fat cells, making it less accessible to your body if you are obese. In this case, higher doses of vitamin D supplements may be appropriate, and it’s recommended to consult your doctor.
  • Crohn’s disease, cystic fibrosis, and celiac disease are all conditions whereby your body might have difficulty absorbing vitamin D, even from supplements.
  • Weight loss surgeries, such as gastric bypass surgery, may interfere with vitamin D absorption (and other nutrients as well)—making regular testing and discussions with your doctor extra important.
  • Kidney and liver disease reduce the amount of specific enzymes that your body uses to convert vitamin D to a form it can use, thereby leading to vitamin D insufficiencies.
  • There are several medications that may lower your vitamin D levels, such as: laxatives, cholesterol-lowering drugs, steroids and others.

If you have any of the conditions or take any of the medications (read more here) just listed, having on-going discussion with your doctor and regular testing of your vitamin D levels — these discussions are extra important.

BLOG: Vitamin D and Kidney Stones: Is There an Association?


Limited Dietary Sources 

The fact is, it’s very difficult to get the amount of vitamin D you need from food alone. Sure, you can get some vitamin D from salmon (that’s one of the richest sources of the vitamin) and other fatty fish, and smaller amounts from cheese, egg yolks and mushrooms, but there just aren’t a lot of foods in nature that contain vitamin D. Some fortified foods like milk, orange juice and cereal have added vitamin D (check the label!), but how much cereal can you (or maybe the better question is ‘should’ you) eat in one day?

BLOG: Can Low Vitamin D Cause Fatigue?

It’s the lack of dietary sources for vitamin D that also make it difficult for people to stay in the sufficient level for this vitamin and even harder for those who choose not to take vitamin D (or multivitamin) supplements.

VIDEO: Getting Vitamin D from Supplements


What are Some of the Symptoms of Vitamin D Deficiency/Insufficiency?

Fatigue, muscle weakness, back pain, joint pain, problems sleeping, hair loss, headaches and depression. These are some of the symptoms associated with a lack of vitamin D; however, as you know, these symptoms are also related to other health conditions.

Fortunately, there is a way to find out for sure if you have a vitamin D insufficiency or deficiency.


How Can You Know if You Have a Vitamin D Deficiency or Insufficiency?

In one word: testing.

The only way to learn if you are lacking in vitamin D is through a blood test, either prescribed by a doctor and administered in-office or at an outside lab, or through an at-home test. A prescribed blood test will draw blood with a small needle inserted in your vein, while an at-home test is usually a simple finger prick blood test that is then sent back to a lab for analysis.

With both types of tests, the results will have measured the amount of vitamin D in your blood, expressed in either nanomoles per liter (nmol/L) or nanograms per milliliter (ng/mL).

Here are what leading experts say about what specific blood level targets based on 25(OH)D levels:

  • The Institute of Medicine (IOM) reports that people are at risk of vitamin D deficiency at <12 ng/mL; insufficiency at 12-<20 ng/mL; 20 ng/mL is considered adequate; and >50 ng/mL could be considered toxic, as reported in this article.
  • At OmegaQuant, we have set the following levels for vitamin D as follows: deficiency at <10 ng/mL; insufficiency at 10-20 ng/mL; 20-30 ng/mL as sufficient; >30-50 ng/mL is desirable; and >100 ng/mL is considered excessive and not recommended.


Treating Vitamin D Deficiency

Here’s a fortunate fact: vitamin D deficiency is generally treatable (and also mostly preventable) if you’re testing your blood levels regularly and taking steps to improve your vitamin D status, as needed.

You can start by increasing your sun exposure safely and consistently—but in small doses and always protected. Have that conversation with your dermatologist or other doctor, especially if you have a family history of skin cancer or have personally had skin cancer or other cancers.

To the extent that you can improve your diet to include more vitamin D-rich foods, like fatty fish, do so.

Your doctor may want to prescribe a high dose vitamin D pill for a short period of time to boost your levels and give you a chance to bring you out of deficiency more quickly.

Taking vitamin D supplements is a perfectly reasonable, rational choice to fill in vitamin D nutrient gaps. If you’re deficient or insufficient in vitamin D, your doctor may recommend taking a higher dose than the label suggests. Check with him/her. Be sure to test after about 3 months of that dose to see if your vitamin D levels have improved.

Once you reach vitamin D sufficiency, maintain what you’re doing and test again. With our OmegaQuant at-home test, we recommend every six months to be sure that you’re staying within the right range. We also recommend you discuss results and retesting options with your doctor, whether you are using an at-home test or a prescribed test.

When retesting your levels, you’ll also want to watch to be sure you’re not reaching a number that represents potential excess. Although vitamin D toxicity is rare, as with everything, too much of a good thing may not actually be good for you.

VIDEO: How do you know if you are getting to a healthy vitamin D level?


How Long Does It Take to Recover from Vitamin D Deficiency?

The good news here is that recovering from a vitamin D deficiency involves a relatively reasonable timeframe. According to this article, taking vitamin D supplements for 8-12 weeks could result in a significant increase in your vitamin D blood levels. This article is even more optimistic, advising that taking 1,000 IU of supplemental vitamin D3 is expected to raise blood levels by 10 ng/mL after a few weeks. It really depends on your individual circumstances.

A doctor-prescribed high weekly dose (e.g., 50,000 IU) of D2 is another option and may take around 12 weeks to get you to where you should be, given that the body generally absorbs D3 more efficiently than D2. Read more about D3 vs. D2.

BLOG: Should you take Vitamin D2 or D3?

But don’t consider this a one and done situation. First, it is important to talk with your doctor about how to proceed to raise your D blood levels. You may need to continue to take vitamin D supplements to maintain sufficient or optimal levels even once you’ve reached them. The only way to know for sure is to test your vitamin D blood levels regularly.

VIDEO: When should you take a vitamin D test?

These statements have not been evaluated by the Food and Drug Administration. This test is not intended to diagnose, treat, cure, prevent or mitigate any disease. This site does not offer medical advice, and nothing contained herein is intended to establish a doctor/patient relationship. OmegaQuant, LLC is regulated under the Clinical Laboratory improvement Amendments of 1988 (CLIA) and is qualified to perform high complexity clinical testing. The performance characteristics of this test were determined by OmegaQuant, LLC. It has not been cleared or approved by the U.S. Food and Drug Administration.

Sign up for our Newsletter and save 10%*

Join our mailing list to get the latest news and updates from OmegaQuant.

You have successfully subscribed! Use code NEWSLETTER10 to receive 10% off your next purchase*.