Symptoms of vitamin D deficiency: Common and weird signs

In this article:

• What is vitamin D, and why is it important?
• Most common symptoms
• Weird symptoms
• Severe and long-term symptoms
• Who is most at risk for vitamin D deficiency?
• How to prevent and treat vitamin D deficiency?
• When to see a healthcare provider
• Can you take too much vitamin D?

In this article

• What is vitamin D, and why is it important?
• Most common symptoms
• Weird symptoms
• Severe and long-term symptoms
• Who is most at risk for vitamin D deficiency?
• How to prevent and treat vitamin D deficiency?
• When to see a healthcare provider
• Can you take too much vitamin D?

You need vitamin D to build strong bones, fortify your immune system, and maintain mental clarity, but it can be tough to get enough of this important nutrient without taking supplements. Watching for common or even weird symptoms of a vitamin D deficiency can help you take action to prevent more severe symptoms. However, it’s important to talk to your healthcare provider about routine vitamin D screening because some people notice no signs of a deficiency at all. 

What is vitamin D, and why is it important?

Vitamin D is an essential nutrient that helps your body grow strong, stay healthy, and perform physical and mental tasks. Here’s a quick look at some of its most important functions: 

• Helps the body absorb calcium and promotes ongoing bone health
• Supports the immune system and helps prevent infections
• Lowers the risk of autoimmune diseases like lupus, multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease
• Improves muscle strength and postural stability
• Keeps the brain healthy as it ages
• Helps with mood regulation and improves or prevents depression and anxiety

Our bodies make their own vitamin D whenever sunlight touches our skin. It’s also naturally found in some foods and artificially added to others. Not getting enough sunlight and not eating enough vitamin D-rich foods can contribute to a vitamin D deficiency. 

What are the most common symptoms of vitamin D deficiency?

The most common signs of vitamin D deficiency vary by age. Children may complain of pain in their bones and muscles and exhibit signs of weakness, joint deformities, and bowed or bent bones (medically known as rickets). Irritability and developmental delays can also occur.

Most adults with vitamin D deficiency notice no signs or symptoms. Those who do experience symptoms commonly report bone pain, fatigue, and muscle weakness, pain, or twitching. 

“It’s incredibly easy to mistake vitamin D deficiency for other medical conditions because its primary symptoms match signs of fibromyalgia, chronic fatigue syndrome, or clinical depression,” says Gail Clifford, MD, an internal medicine hospitalist based in Connecticut. 

“Many patients are told their exhaustion is just part of being busy or aging, when in reality their vitamin D serum levels are critically low. Additionally, vitamin D’s absence can cause mood swings and brain fog that looks identical to perimenopause or a thyroid imbalance.” 

Weird symptoms of vitamin D deficiency

A vitamin D deficiency can cause wide-ranging and unexpected symptoms that some may consider to be “weird.”

“Some patients experience burning mouth syndrome or a metallic taste,” Dr. Clifford says. “Others report chronic bone tenderness, where it hurts to press on their shins or breastbone. There are also reports of restless legs syndrome and surprisingly stubborn cases of adult acne that flares up when vitamin D levels drop.” 

Jeffrey H. Chester, MD, a doctor of osteopathic medicine based in Kailua Kona, Hawaii, says he’s seen vitamin D deficiencies change people’s behavior. “For example, a person who has generally always been pretty disciplined and organized might start procrastinating. This is actually due to the way vitamin D can influence insulin, dopamine, and serotonin levels, which are tied to things like motivation and focus.” 

Dr. Chester adds that it can be easy to confuse symptoms of low vitamin D for things like depression, ADHD, anxiety disorder, chronic fatigue syndrome, and neuropathy.

Other weird symptoms of a vitamin D deficiency include:

• Frequently getting sick
• Infections that take a long time to heal
• Night sweats

Severe vitamin D deficiency can lead to secondary hyperparathyroidism, a condition characterized by excessive secretion of parathyroid hormone. When this happens, you may notice symptoms like: 

• An increase in urination and thirst
• Nausea
• Vomiting
• Poor appetite
• Constipation
• Abdominal pain
• Difficulty concentrating

The amount of calcium in your blood may also get too low when you have a vitamin D deficiency. Also known as hypocalcemia, this condition causes a range of symptoms depending on how low your blood calcium levels get. A mild case of hypocalcemia can contribute to muscle cramping, particularly in the legs and back. Other symptoms of mild hypocalcemia may include the following:

• Dry, scaly, or itchy skin
• Brittle nails
• Coarse hair growth

Severe or long-term symptoms of vitamin D deficiency

If common or weird symptoms of vitamin D deficiency aren’t addressed early, they can become severe or long-term. 

For example, if hypocalcemia is left untreated, you may begin to experience more psychological symptoms, like depression, irritability, memory problems, confusion, or hallucinations. Critically low blood calcium levels can cause seizures, an irregular heartbeat, tingling in your feet, fingers, tongue, or lips, difficulty breathing, stiff muscles, or congestive heart failure.

Long-term or severe vitamin D deficiency also increases the risk of bone conditions like osteoporosis and osteomalacia. Osteoporosis occurs when the bones lose some of their density, causing them to become thinner and more fragile. Osteomalacia occurs due to a defect in the bone hardening process, leading to bones that become soft and weak.

Symptoms of osteoporosis and osteomalacia include the following:

• Bone pain, especially in the legs, hips, and pelvis
• Frequent falls
• Changes in the way you walk, or difficulty walking
• Changes in posture
• Bone fractures
• Muscle cramps or spasms, particularly in the hands and feet
• Tingling in the arms and legs
• Lower back pain
• Shrinking an inch or more in height
• Shortness of breath from spinal compression

Who is most at risk for vitamin D deficiency?

Anyone can become deficient in vitamin D by not eating vitamin D-rich foods or by failing to get enough sunlight. However, other risk factors can make it tougher for the body to use vitamin D.

Diet

Certain mushrooms and a few animal-based foods, including fatty fish, beef liver, egg yolks, and cheese, contain vitamin D. It’s also added to some foods, like breakfast cereals, orange juice, and milk, to help people get enough in their diet. Those who don’t eat enough natural or fortified sources of vitamin D may be at an increased risk of vitamin D deficiency. 

Sun exposure

People may not get enough sunlight for a variety of reasons, like working the night shift or staying indoors due to health problems. But you may not get enough vitamin D even if you spend plenty of time outside.

Vitamin D production is also affected by how far you are from the equator, the time of year, cloudy days, and how much skin is actually exposed to the sun. 

Skin tone

Having a darker skin tone means your body may not efficiently create vitamin D in response to sunlight. Skin pigment called melanin acts as a natural sunblock. People with high amounts of melanin need a lot more sun exposure for adequate vitamin D synthesis compared to people with low amounts of melanin. 

Health conditions and medications

Sometimes a vitamin D deficiency develops because of medical conditions that change the way the body absorbs or produces vitamin D. This may happen due to digestive disorders, kidney disease, or obesity. Certain medications can also increase your risk of vitamin D deficiency. 

Age

People aged 65 and older are more likely to become deficient in vitamin D. Over time, the skin naturally loses some of its ability to synthesize this nutrient. Babies exclusively fed breast milk are also at greater risk of vitamin D deficiency. 

RELATED: Why would I need a vitamin D prescription?

How to prevent and treat vitamin D deficiency?

Exposing your skin to safe levels of sunlight and eating foods rich in vitamin D may be enough to prevent a deficiency. However, your healthcare provider may recommend taking vitamin D supplements if you’re already deficient or are at an increased risk of deficiency. 

There are two main types of vitamin D: D2 and D3. Vitamin D2 is usually found in fortified foods. However, it is not as well absorbed in the body as vitamin D3. Your body creates Vitamin D3 in response to sunlight, and you can increase your D3 levels by eating certain animal-based foods. Researchers have found that vitamin D3 supplements may be more effective at treating vitamin D deficiencies. 

You can buy low doses of both types in over-the-counter vitamin D supplements. There are also high-dose vitamin D supplements available with a prescription for people with severely low vitamin D levels. Talk to a healthcare provider before starting a vitamin D supplement to make sure it won’t interact with other medications or cause elevated vitamin D. 

When to see a healthcare provider

About 35% of U.S. adults have low levels of vitamin D, but many people don’t experience any symptoms. To make sure a vitamin D deficiency doesn’t go untreated for too long, ask your healthcare provider how often you should get your levels checked. Vitamin D deficiency is diagnosed through a simple blood test that’s often run at annual check-ups. Find out if you’re regularly getting tested, and ask for a vitamin D test if not. If your test is done in the summer, consider getting tested again in the winter when there’s less sun exposure.

If you always feel tired no matter how much you sleep, notice persistent mood issues like depression or anxiety, or have unexplained bone and muscle pain, don’t wait for your annual checkup. Talk to a healthcare provider right away about a vitamin D test. A simple supplement may be all it takes to improve your quality of life.  

Can you take too much vitamin D?

Although vitamin D supplements are available over the counter (OTC), you should talk to a healthcare provider before starting them. Too much vitamin D can cause some of the same symptoms of vitamin D deficiency, like muscle pain and mood disorders, plus some additional symptoms like kidney stones. Typically, your healthcare provider will run a blood test to see if you need any supplements at all. Then, they’ll run regular follow-up tests to make sure your levels improve but don’t get too high. 

Some people need a much greater dose of vitamin D than what’s available in over-the-counter supplements. High-potency vitamin D is only available with a prescription. Talk to your healthcare provider about the pros and cons of each, and ask which strength is appropriate for you. 

Bottom line

Don’t start taking supplements without talking to your healthcare provider. They can review other medications and supplements you’re taking to make sure there aren’t any negative interactions. They may even be able to write you a prescription for vitamin D, even if it is a low dose, so you can save with SingleCare coupons. They’re typically happy to help patients save.  

RELATED: Can I use a prescription savings card for over-the-counter (OTC) medications?