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Signs of Vitamin D Deficiency: What You Need To Know

Written by 
Lacey Ramburger
Reviewed by 
Dr. Rene Roberts, MD
Article at a glance
  • Vitamin D is an essential nutrient that helps the body absorb calcium, as well as aid muscles, nerves, and the immune system.

  • Vitamin D deficiency is one of the most common vitamin deficiencies, which can contribute to osteoporosis, loss of bone density, and depression.

  • Vitamin D deficiency can be countered by consuming more vitamin D through supplements, spending more time in the sun, or administering prescription medications to regulate vitamin D levels.

What Is Vitamin D?

Vitamin D is a vital nutrient that has a big impact on the function of the human body. It is a fat-soluble vitamin that helps the body absorb calcium, which contributes to strong bones and bone health. It is available in both food/​beverages as well as supplements. In supplements, there are two types of vitamin D: D2 and D3. Both versions increase vitamin D in the bloodstream, though D3 may raise and keep levels of vitamin D higher over time.

Vitamin D is created when bare skin has exposure to sunlight—and sun exposure is one of the main ways humans receive Vitamin D. However, certain factors and conditions may make the possibility of vitamin D deficiency a higher risk.

Importance of Vitamin D

Outside of its important role in absorbing calcium, vitamin D also helps in the prevention of certain conditions, such as:

  • Osteoporosis: a bone disease that results from a decrease in bone mass and bone mineral density—vitamin D is known to aid in bone health.

  • Cancer: some research shows that those with abnormal levels of vitamin D may be at a higher risk for certain types of cancer.

  • Certain autoimmune diseases: vitamin D is shown to help regulate immune function; without proper levels of the vitamin, there is an increased risk of immune-related diseases.

How Much Vitamin D Does a Person Need?

Side View of an Elderly Woman Wearing a Sun Visor

The amount of vitamin D a person needs is dependent on a few factors and should be monitored given that having too much vitamin D can also cause health risks. According to the National Institutes of Health and Human Services, these are the upper limits (or the highest amount) of vitamin D, measured in micrograms, a person requires each day:

  • Birth to 6 months: 25 mcg

  • Infants 7–12 months: 38 mcg

  • Children 1–3 years: 63 mcg

  • Children 4–8 years: 75 mcg

  • Children/​Teens 9–18 years: 100 mcg

  • Adults: 100 mcg

  • Pregnant and breastfeeding teens and women: 100 mcg

How Common Is Vitamin D Deficiency?

Despite its reputation as the sunshine” vitamin, vitamin D deficiency still occurs regularly without a lack of sun exposure as the cause. Certain conditions, skin color, and age can all cause issues for a person trying to obtain their daily dose of vitamin D. In fact, vitamin D deficiency is one of the most common vitamin deficiencies—The National Library of Medicine states that up to 1 billion people worldwide experience some sort of deficiency with vitamin D.

Conditions Causing Vitamin D Deficiency

While vitamin D seems fairly accessible due to its creation from sunlight exposure to the skin, there are a few reasons why a person may experience vitamin D deficiency.

Plenty of factors can set the stage for vitamin D deficiency, including:

  • Having chronic kidney disease or liver disease as kidneys play a role in converting vitamin D into an active form used by the body.

  • Having a condition that interferes with vitamin absorption, such as Crohn’s disease or Celiac disease.

  • Taking certain medications that affect vitamin D absorption, such as steroids.

  • Too high or too low levels of parathyroid hormone as parathyroid hormone is a major stimulant for synthesizing vitamin D in the kidneys.

Signs of Vitamin D Deficiency

Those who experience vitamin D deficiency usually may not experience symptoms for months or years. In some cases, people don’t experience symptoms at all. Nonetheless, there are still signs and symptoms to look out for both physically and psychologically

Physical Symptoms of Vitamin D Deficiency

  • Constant Illness and Infections: due to its role in immune health, those who don’t receive enough vitamin D may notice frequent illnesses, such as the cold or flu, and immune diseases occurring.

  • Bone Pain: a lack of vitamin D can result in weakened bones, causing body pain or soreness.

  • Slow Wound Healing: vitamin D additionally plays a role in lowering inflammation, and some research indicates that vitamin D aids in the creation of new skin.

  • Hair Loss: some studies have linked hair loss, most notably in women, with not enough vitamin D.

  • Bone Loss: given the nutrient’s role in calcium absorption and bone metabolism, vitamin D deficiency can contribute to low bone mineral density.

Neurological Symptoms of Vitamin D Deficiency

  • Pins and Needles” sensation in hands and feet

  • Difficulty walking or moving around due to muscle weakness 

  • Increased sensitivity to pain

  • Some studies link low vitamin D deficiency to neurological disorders, such as multiple sclerosis

Psychological Symptoms of Vitamin D Deficiency

Vitamin D deficiency can potentially affect cognitive skills and may cause issues such as:

  • Depressive symptoms

  • Anxiety

  • Mood changes

Risk Factors For Vitamin D Deficiency

doctor and patient talking in hospital room

Some may be at higher risk for developing a vitamin D deficiency, including:

  • Stomach Surgery Patients: if a person has an operation on their stomach, such as weight loss surgery or the removal of cancerous tumors, it can affect the body’s ability to retain vitamin D.

  • Those with Darker Skin: higher amounts of melanin can reduce the skin’s ability to create vitamin D from sunlight—however, research is still needed to see if lower levels of vitamin D in those with darker skin actually produces the same adverse side effects as those with lighter skin.

  • Those Taking Certain Medications: some medications, such as steroids, statins (to reduce cholesterol synthesis), or the weight loss drug Orlistat makes it difficult to absorb vitamin D. Additionally, those who take thiazide diuretics may experience interference with receiving proper vitamin D levels.

  • Older Adults: as a person ages, their skin’s ability to synthesize vitamin D decreases, meaning they may experience issues with obtaining proper vitamin D levels.

  • Breastfed Infants: breastfed infants may have issues receiving vitamin D, given that breast milk doesn’t usually contain high levels of the nutrient. Newborn children are also not advised to have much direct sun exposure, increasing the chances of vitamin D deficiency.

  • Certain locations: those living in regions that don’t receive much sunlight may not receive enough vitamin D due to lack of sun exposure.

Vitamin D Deficiency in Older Adults

While different groups of people can experience lower vitamin D levels, older adults are specifically at a higher risk of experiencing it. 

Age itself is a factor in a lack of vitamin D, most notably because older adults have a higher likelihood of developing conditions that contribute to vitamin D deficiency, including:

  • Diabetes

  • Crohn’s disease

  • Less time spent outdoors

  • Kidney disease

Additionally, as a person ages, their diet may not be as well-rounded as it once was, or a lack of appetite may prevent older adults from eating food and beverages that contain an adequate amount of vitamin D. Certain medications may also interfere with the body’s ability to absorb and retain vitamin D.

How Vitamin D Deficiency is Diagnosed

Three women hugging outside in workout gear

To determine vitamin D deficiency, a physician may choose to do a blood test to measure vitamin D levels. The most commonly used option is the 25-hydroxy vitamin D test, which is considered to provide the best results.

Vitamin D tests and screenings can be expensive and are not often recommended to do regularly. However, for those who are at a higher risk of vitamin D deficiency, a test may be requested.

How To Treat Vitamin D Deficiency

doctor in mask with patient on couch

If vitamin D deficiency is detected, there are a few different treatment options available, including:

  • Prescription Vitamin D Supplementation: these are typically used in cases of severe vitamin D deficiency, and are much higher in dosage than regular vitamin D supplements.

  • Vitamin D Supplement: in less severe cases, taking Vitamin D dietary supplements (including multivitamins) can help provide the appropriate amount of Vitamin D. It’s also recommended to take magnesium, as it can help activate vitamin D supplements.

  • Fortified Foods: given that vitamin D isn’t contained naturally in most food or beverages, some options that are fortified with Vitamin D can help make up for the lack of the nutrient.

Sources of Vitamin D

There are a few sources of vitamin D foods and beverages that a person can obtain vitamin D from. These are typically divided into two categories: foods that contain B12 naturally and those that artificially include vitamin D for added nutrients known as fortified foods.

Foods That Naturally Contain Vitamin D

Some examples of foods that naturally contain the nutrient include:

  • Beef liver

  • Swordfish

  • Tuna

  • Salmon, fatty fish

  • Egg yolks

  • Sardines

  • Cod liver oil

Fortified Foods That Contain Vitamin D

Some examples of fortified foods that artificially contain the vitamin D nutrient include:

  • Fortified Dairy and Non-Dairy milk (certain ones)

  • Fortified breakfast cereals

  • Fortified fruit juices

Can Too Much Vitamin D Be Dangerous?

While obtaining adequate vitamin D levels is essential for good health, it is possible to consume too much vitamin D. If vitamin D levels are too high, unwanted side effects can occur, including:

  • Nausea

  • Vomiting

  • Muscle weakness

  • Confusion

  • Excessive urination

  • Dehydration

  • Kidney stones

In severe cases, high doses of vitamin D can result in kidney failure, irregular heartbeat, or death.

The common cause of too much vitamin D is from taking too many dietary supplements—a person cannot receive too much vitamin D from the sun due to the body’s ability to regulate how much it creates. Spending too much time in the sun without proper SPF protection is also not advised, as it can increase the risk factor of developing skin cancer.

When To Speak To Your Healthcare Provider

Clear Plastic Container and Medicine Capsule

One of the larger issues surrounding vitamin D deficiency is how subtle the symptoms can be. Even when you are not actively absorbing the nutrient from food or supplements, it can take years for a vitamin D deficiency to make itself known.

Additionally, some symptoms can also be mistaken for other conditions or illnesses, making it difficult to know when to see a physician. Here are some things to keep in mind:

  • Contact your doctor if you are experiencing multiple symptoms of vitamin D deficiency: regardless of the cause if you are dealing with consistent symptoms such as bone pain, constant immune infections, or depression, it’s important to contact your healthcare provider and see about taking a blood test to determine your vitamin D levels.

  • If you experience new or worsening symptoms: if your doctor has already informed you that you have low levels of vitamin D and you develop new or worsening symptoms, contact your healthcare provider immediately.

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