Man standing against yellow background feeling fatigued and wondering about the signs of vitamin D deficiency

Symptoms of Low Vitamin D: What Are the Signs of Vitamin D Deficiency?

Medically reviewed by Neka Miller, PhD on February 15, 2021. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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It’s possible to become deficient in vitamin D—if, for example, you aren’t getting enough vitamin d from the sun. When that happens, one or more vitamin D deficiency symptoms could start affecting you. So what are the signs of vitamin D deficiency to be aware of?

That’s what we’re covering here—so read on to learn more about the signs of low vitamin D, how vitamin D deficiency happens, and more.

Wondering if your vitamin D levels might be too low? Easily check your vitamin D status with the Everlywell at-home vitamin D deficiency test.

What Is Vitamin D?

Your body requires a variety of vitamins, minerals, and nutrients to function efficiently, fight off infections, and maintain your overall health. However, you generally cannot generate these nutrients on your own, meaning that you have to get them from your diet or through supplements.

Vitamin D is the one exception. Out of 13 essential vitamins, it is the only one your body can make on its own because vitamin D production is triggered when your skin is exposed to ultraviolet radiation from sunlight. This is often why vitamin D is referred to as the “sunshine vitamin.”

Vitamin D is a fat-soluble vitamin that serves important functions in the body. Most notably, vitamin D ensures proper absorption of calcium in the gut to build strong and healthy bones and maintain proper bone mineralization. In children and young adults, vitamin D is also necessary for bone growth and development.

Along with its role in bone health, vitamin D helps control aspects of cell growth and immune function—and it may play a role in reducing inflammation and the production of insulin.

Vitamin D Deficiency Signs and Symptoms

Here are some of the most common signs of vitamin D deficiency in adults:

  • General fatigue
  • Weight gain
  • Bone pain
  • Hair loss
  • Weakened muscles
  • Muscles cramps or aches
  • Depression or sudden mood changes

As you can see, many low vitamin D symptoms are fairly general in nature and could also be signs of some other condition. So if you’re experiencing any of the above, get in touch with your healthcare provider to learn what they recommend next. You may also be interested in checking your vitamin D levels, which you can easily do with the Everlywell at-home Vitamin D Test.

Related: Vitamin D Deficiency: What Role Does It Play in Weight Gain?

In children, low vitamin D levels can lead to rickets, which is characterized by a softening and weakening of the bones. This can lead to certain skeletal deformities, including bowed legs, thick wrists or ankles, and a projected breastbone. Other symptoms of rickets include:

  • Delays in physical growth and development
  • Delayed motor skills
  • General muscle weakness
  • Pain in the legs, pelvis, and spine

In adolescents and adults, low vitamin D levels can result in osteomalacia. Similar to rickets, osteomalacia is marked by a softening of bones. In its early stages, osteomalacia presents no symptoms, though bone health changes can show up on X-rays. As the condition progresses, you can develop weakening muscles and a dull, aching pain in your bones. This pain can be worse at night and whenever you put pressure on your bones. This mostly affects these parts of the body:

  • Legs
  • Ribs
  • Hips
  • Pelvis
  • Lower back

As the pain and muscle weakness in the legs increase, you may develop a more waddling gait that contributes to walking difficulties. In older adults, osteomalacia puts one at an increased risk of bone fractures.

Along with changes in bone density and possible muscle pain, vitamin D deficiency may be associated with other complications, including:

  • High blood pressure and heart disease
  • Immune system disorders
  • Diabetes
  • Certain forms of cancer (breast cancer, colon cancer, prostate cancer)
  • Multiple sclerosis

Falls can become much more common among older adults with low vitamin D levels. Also, because calcium plays a vital role in dental health, vitamin D deficiencies can lead to teeth deformities.

How Vitamin D Deficiency Happens

Vitamin D is the only vitamin that your body can make on its own (instead of having to get it from dietary sources), so why should you experience deficiencies in the first place? Although the body can make vitamin D on its own, direct contact of skin with sunlight is necessary for this to happen. Clothes and sunblock can prevent that, but other factors that can affect sun exposure include:

The season: Fall and winter naturally bring shorter days, along with clouds that obscure the sun. The time of day: The sun is most active from 10 am to 3 pm. If you are inside for that period, you may not get enough sunlight to trigger enough vitamin D production.

Vitamin D production can also be stunted by certain diseases and health conditions. Cystic fibrosis, celiac disease, and Crohn’s disease can prevent the intestines from properly absorbing vitamin D in foods. Kidney and liver diseases can reduce the enzymes needed to process vitamin D and turn it into a usable form in the body.

Other factors that may contribute to vitamin D deficiency include:

  • Skin color: Having darker skin requires more sun exposure for ample amounts of vitamin D to be produced.
  • Age: As you age, your body’s ability to create and process the "sunshine vitamin" generally declines.
  • General mobility and lifestyle: Being homebound or otherwise not being able to go outside reduces your sun exposure. People who work night shifts and sleep during the day may also have trouble getting enough sunlight.

How Much Vitamin D Do You Need?

About 15 to 20 minutes of direct exposure to sunlight three days per week is usually sufficient. If you don’t have access to that much sun based on your lifestyle or where you live, the good news is that you can get vitamin D from sources other than the sun.

Vitamin D is naturally found in fatty fish, and it is often added to foods (known as “fortified foods”), including milk, yogurt, cereal products, and orange juice. Vitamin D is also available in over-the-counter dietary supplements.

For adults, the recommended dietary allowance is 600 - 800 IUs (International Units) of vitamin D per day, depending on one’s age. Adults older than 70 should get up to 800 IUs of vitamin D per day. (Be sure to always talk with your healthcare provider before incorporating new vitamin or mineral supplements into your diet.)

However, you can have too much of a good thing. Excessively high levels of vitamin D (or vitamin D toxicity) can cause calcium to build up in the blood, which can lead to weakness, frequent urination, nausea, and vomiting. This is also one of the vitamins that cause constipation if taken excessively. You may even develop bone pain and kidney stones. This, however, is incredibly rare and is almost always the result of over-supplementing with vitamin D (you can’t get vitamin D toxicity just through exposure to sunlight).

Check your vitamin D levels from the convenience of home with our easy-to-use vitamin D blood test. You just collect a small sample of blood (via a simple finger prick), send it to a lab for testing (a prepaid shipping label is included with the kit), and get digital results in days.

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  1. Vitamins. Medline Plus. Accessed February 15, 2021.
  2. Vitamin D. NIH, Office of Dietary Supplements. Accessed February 15, 2021.
  3. Vitamin D Deficiency. Cleveland Clinic. Accessed February 15, 2021.
  4. Rickets. Mayo Clinic. Accessed February 15, 2021.
  5. Osteomalacia. Mayo Clinic. Accessed February 15, 2021.
  6. What is vitamin D toxicity? Should I be worried about taking supplements? Mayo Clinic. Accessed February 15, 2021.
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