Vitamin D Deficiency Symptoms & Sources to Reverse It!

Would you believe that the majority of the population — between 40 percent and 90 percent or more of adults in the U.S., depending on race — is believed to have a vitamin D deficiency? That’s makes it on the most common nutrient deficiencies.

It’s no wonder that this vitamin is now one of the most recommended supplements by physicians, taken in order to treat and/or prevent vitamin D deficiency symptoms.

People with dark skin, those who live in northern regions of the world where there’s less year-round sun exposure and those who are overweight have an even greater chance of experiencing vitamin D deficiency.

Can vitamin D deficiency be cured? Yes, there are ways you can naturally increase your vitamin D levels and decrease your risk of developing related health conditions.

Spending time in the sun, without sunscreen, is your surest way to get enough. Eating vitamin D-rich foods also helps improve your blood levels.

Read on to understand just how much time you need in the sun and what foods help you avoid vitamin D deficiency.

What is vitamin D?

Vitamin D is a fat-soluble vitamin that’s stored in the liver and fatty tissues. It’s somewhat different than other vitamins because the body makes most of it on its own (with the help of sunlight), rather than solely relying on food sources to get enough.

Why do we need vitamin D?

Here are some of the benefits associated with vitamin D:

• Contributes to bone health by aiding in calcium absorption into the bones, as well as other vitamins and minerals that contribute to skeletal health, including magnesium, vitamin K and phosphorus.
• Supports the immune system and may help prevent prolonged or excessive inflammatory responses, plus some viruses and infections.
• Can help support healthy cell replication and may play a role in protecting against the development of autoimmune conditions.
• Promotes cardiovascular health and helps regulate blood pressure, cholesterol levels and inflammation.
• Helps manage blood sugar levels and works with calcium to regulate insulin secretion.
• May help prevent depression and mood disorders, especially during the winter.
• Seems to play a role in preventing obesity. Studies have shown deficiency is tied to greater volumes of fat, serum, liver and muscle mass, although the relationship is still being researched.

Vitamin D deficiency symptoms

What happens when your vitamin D is low? According to scientific studies and reviews, the most common vitamin D deficiency symptoms include:

• fatigue
• osteoporosis
• heart disease and high blood pressure
• cancer
• autoimmune diseases
• depression and mood disturbances
• poor skin health, including redness, inflammation and dryness
• insomnia
• arthritis and joint pain
• diabetes
• trouble concentrating
• asthma
• hair loss
• multiple sclerosis
• chronic muscle or bone pain
• psoriasis
• fibromyalgia

1. Anxiety and depression

Vitamin D deficiency has been linked to increased risk of anxiety and depression in several studies. For instance, a meta-analysis of 61 peer-reviewed articles found a negative correlation between vitamin D levels and depression, indicating that low vitamin D is associated with higher rates of clinical depression.

Other research has shown that vitamin D receptors are present in areas of the brain associated with depression. Vitamin D may stimulate cell growth and function in these regions, suggesting a deficiency could impair brain function related to mood.

2. Back and bone pain

Low vitamin D can lead to bone pain and increased risk of fractures because vitamin D is crucial for calcium absorption and bone metabolism. Deficiency can cause a condition called osteomalacia in adults, which is characterized by bone pain and muscle weakness.

A 2003 study found that 93% of people with persistent, nonspecific musculoskeletal pain were deficient in vitamin D.

3. Bone density loss

Vitamin D deficiency is strongly linked to decreased bone density and osteoporosis. Research has revealed that vitamin D deficiency can lead to decreased calcium absorption, increased bone turnover and bone loss over time.

One study found that low vitamin D levels were associated with increased rates of hip bone loss in older women, for instance.

4. Fatigue

Feeling excessively tired is a common symptom of vitamin D deficiency. A narrative review published in Nutrients relayed that vitamin D supplementation significantly improved fatigue symptoms in a patient with severe deficiency.

Research has suggested vitamin D plays a role in mitochondrial function, which affects energy production in cells. Deficiency may impair this process, leading to fatigue.

5. Frequently dealing with infections or illnesses

Low vitamin D is associated with impaired immune function and increased susceptibility to infections. A meta-analysis published in the BMJ found that vitamin D supplementation reduced the risk of acute respiratory infections.

Studies also have shown vitamin D helps produce antimicrobial peptides that fight bacteria and viruses.

6. Hair thinning and/or hair loss

While more research is needed, some studies have suggested a link between vitamin D deficiency and hair loss. For example, a 2016 study found that women students in South India with hair loss had significantly lower vitamin D levels than those without hair loss.

That’s not all. A review published in 2010 determined that vitamin D may play a role in the hair follicle cycle and new follicle formation.

7. Impaired or delayed wound healing

Vitamin D deficiency may slow wound healing. A study in the Journal of Dental Research found that vitamin D supplementation improved wound healing after dental surgery.

In addition, further research has shown that vitamin D plays a role in controlling inflammation and fighting infection in wounds.

8. Muscle discomfort and pain

Muscle pain and weakness are common symptoms of severe vitamin D deficiency. A study out of Europe found that 71% of people with chronic muscle pain were deficient in vitamin D.

Further research published in the Scandinavian Journal of Primary Health Care confirmed that vitamin D supplementation can help patients with chronic pain, and it was reported that many patients with musculoskeletal pain, fatigue and headaches had low vitamin D levels in 2010 study.

9. Weight gain

Some studies have found a link between low vitamin D and obesity. A study in the American Journal of Clinical Nutrition, for instance, found that people with adequate vitamin D levels lost more weight on a reduced-calorie diet compared to those with low levels.

In addition, studies have shown that vitamin D may influence fat cell formation and metabolism.

Causes/risk factors/health risks

Why do some people develop a deficiency in this vitamin?

It’s believed that one of the biggest reasons that vitamin D deficiency is now a public health problem is because of our modern, primarily indoors lifestyle.

Below is more about the common causes of vitamin D deficiency:

1. Lack of sun

Most children today spend unprecedented hours inside — watching television, playing video games and surfing the internet. Similarly, most adults work indoors, exercise inside gyms and spend their free time inside their homes where they are sheltered from the sun.

With all this time indoors, it’s no wonder we don’t get enough of the “sunshine vitamin” and that vitamin D deficiency affects more than a billion people worldwide.

2. Frequent use of sunscreens

As the risk for developing skin cancer has also risen in recent years, doctors strongly encourage the use of sunscreen for children and adults, even through the winter months and when sun exposure is generally limited.

Alarmingly, some research shows that when you wear sunblock SPF 8, you reduce your body’s ability to make vitamin D by 90 percent.

If you choose a sunblock with a higher SPF of 30 (which is the number normally recommended by doctors), you reduce your body’s ability by up to 99 percent. This results in further deficiencies because even though we spend time outdoors, the sunscreen doesn’t allow our bodies to convert vitamin D from the sun.

Other vitamin D deficiency causes and risk factors include:

• Underlying health conditions — Research has shown that certain health conditions, such as abdominal obesity, type 2 diabetes, insulin resistance and hypertension, also increases a person’s risk of vitamin D deficiency.
• Having darker skin — According to the National Health and Nutrition Examination Survey, the newest statistics demonstrate that more than 90 percent of people with darker skin pigments (including African-Americans, Hispanics and Asians) living in the United States now suffer from vitamin D insufficiency, while 75 perfect of the white population is deficient.
• Certain occupations — A 2017 study recently revealed that occupation can also play a big role in levels of this vitamin. Researchers found that shift workers, healthcare workers and indoor workers are at a high risk of developing a deficiency due to reduced outdoor time.
• Being overweight — As the population of overweight and obese adults and children has risen steadily over the past several decades, so has the incidence of vitamin D deficiency symptoms. Sadly, research has shown that vitamin D deficiency is correlated with increased risks of developing common cancers, autoimmune diseases, hypertension and various infectious diseases, too.
• Lack of vitamin D foods in the diet.
• Location — People living in certain parts of the world, particularly regions far from the equator like Northern Canada and Alaska, may have limited access to sunlight, especially during winter months. This reduced sun exposure can lead to decreased vitamin D production in the skin. Additionally, those living in hot climates may avoid spending time outdoors due to extreme heat, also limiting their sun exposure.
• Pollution — Air pollution can block UVB rays from reaching the skin, reducing the body’s ability to synthesize vitamin D. People living in highly polluted areas may also be more likely to stay indoors, further limiting their sun exposure.
• Nutrient absorption issues — Medication conditions such as Crohn’s, celiac and other gastrointestinal disorders can impair nutrient absorption in the intestines, including vitamin D.
• Certain medications — Some medications can interfere with vitamin D metabolism or absorption, such as cholesterol-lowering drugs, anti-seizure meds, steroids and weight loss drugs.
• Smoking — Research has shown that smoking is associated with lower levels of vitamin D, although the exact mechanism is not fully understood.
• Older age — As people age, their skin becomes less efficient at producing vitamin D when exposed to sunlight. Additionally, older adults may have reduced kidney function, which can affect the conversion of vitamin D to its active form in the body.
• Kidney and liver issues — Chronic kidney disease and liver disease can impair the body’s ability to convert vitamin D into its active form. This is because the liver and kidneys play crucial roles in vitamin D metabolism.
• Pregnancy and breastfeeding — The need for vitamin D may increase during pregnancy. While some studies have suggested that vitamin D supplementation during pregnancy may have benefits, there is still ongoing research to determine the optimal approach. Human milk is naturally low in vitamin D, putting breastfed infants at risk of deficiency. For this reason, it’s recommended that breastfed infants receive a vitamin D supplement of 400 international units per day.

Is vitamin D deficiency serious?

Public health experts tell us that it can be, and it’s now linked with a growing number of health conditions, such as heart disease, cancer, diabetes and mood-related problems.

Here are some of the potential health risks that may be associated with vitamin D deficiency:

• Weakened bones — A deficiency in vitamin D can result in the softening of your bones, which is called osteomalacia, or a bone abnormality called rickets. Additionally, a deficiency increases your risk for developing osteoporosis and experiencing fractures or broken bones. This is an especially big risk among older adults.
• Susceptibility to infections and viruses — Low levels have been linked with higher incidence of some serious infections, including those that affect the lungs and respiratory system.
• Mood disorders — Because it acts like a hormone within our bodies and affects brain function, vitamin D deficiency has been linked to an increased risk for mood disorders, including depression, seasonal affective disorder, severe mood problems experienced during PMS, insomnia and anxiety.
• Hormone imbalances — Low levels can interfere with proper testosterone levels and estrogen production, leading to imbalances that can result in many unwanted symptoms.
• Weight fluctuations — Can lack of vitamin D cause weight gain? It’s possible. Some studies have shown that lower levels may be linked to weight gain in older adults, but the weight gain is usually relatively small. There’s more to learn about this connection, but it’s speculated that this vitamin may affect where fat cells shrink or get bigger.
• Cognitive/mental health problems — Researchers have indicated that deficient adults may perform poorer on standardized exams, may have poorer decision-making skills, and may have difficulty with tasks that require focus and attention. Some research has demonstrated a correlation between low levels of vitamin D and an increased risk for developing schizophrenia and multiple sclerosis.
• Susceptibility to some cancers — Vitamin D deficiency symptoms have been correlated with increased risks for cancer development, especially breast, colon and prostate cancers. According to research published in Frontiers in Endocrinology, D vitamin plays a role in factors that influence tumor growth, cell differentiation and apoptosis. Research has shown that it can affect the risk of breast, colon and ovarian cancers, possibly due to its role in the cell life cycle or its ability to block excess estrogen.

Treatment/prevention

How can you increase your vitamin D level? While some foods provide vitamin D, exposure to sunlight is still the best way to get the amount you need in order to prevent vitamin D deficiency symptoms.

However, research has shown that eating foods that are rich in vitamin D and calcium also helps you acquire more, so try adding high-quality, natural sources into your diet regularly.

Importance of sunlight exposure:

Most experts recommend getting about 10 to 15 minutes of direct sunlight daily, without wearing sunscreen, if you are fair- to medium-toned. If you have dark skin, you likely need more time outdoors to make enough vitamin D because you naturally have more protection against effects of UV rays.

Some experts recommend that darker-toned people spend about 40 minutes to one hour in the sun daily if possible.

If it’s the winter, you need to double the recommended time to allow enough vitamin D production to occur.

Here is a good rule of thumb to know that your body is making vitamin D:

• You want to look at your shadow and see that it’s shorter than you are. This tells you that the UV index is high enough.
• Between the hours of 10 a.m. to 3 p.m. is usually when the UV index is highest.

If you are worried about not wearing sunscreen and worried about skin cancer, try applying sunscreen to your face and hands but not on your limbs right away (assuming your limbs are exposed). This leaves enough unexposed skin to properly create the vitamin D you need. 

Overall, increase your levels naturally through the following practices and foods:

1. Sunlight exposure: Aim to spend 10–20 minutes in the sun daily
2. Cod liver oil (take about one tablespoon daily)
3. Halibut
4. Carp fish
5. Mackerel
6. Eel
7. Wild-caught salmon
8. Whitefish
9. Swordfish
10. Rainbow trout
11. Sardines
12. Tuna
13. Pastured eggs
14. Beef liver
15. Milk
16. Caviar
17. Fortified milk and dairy products
18. Fortified milk alternatives, such as nut-based milks
19. Maitake and portobello mushrooms (when exposed to UV light)

How can you raise your vitamin D level quickly? For people who have low levels, vitamin D supplements are available, which come in two forms: D2 and D3.

D3 from animal products (specifically from the cholesterol within these products) is closest to the type humans produce. Vitamin D3 is therefore the more active form and believed to convert much faster than D2.

How much you need

The recommended daily allowance for vitamin D, according to the U.S. Department of Agriculture, is 600 to 800 international units per day for adults. However, getting significantly more, around 5,000 IU per day, may be more effective — especially since there is little risk in over-supplementing in most cases.

Keep in mind that this is a general recommendation, and there is no way to know the exact amount that’s best for you without a blood test. You may need a higher or lower amount and should speak to your doctor and learn about vitamin D side effects as well.

Here are more recommendations based on age:

Dosage recommendation for children:

• 1–3 years: 600 IU (15 mcg/day)
• 4–8 years: 600 IU (15 mcg/day)

For older children and adults:

• 9–70 years: at least 600 IU (15 mcg/day)
• Older adults over 70 years: 800 IU (20 mcg/day)
• Pregnant and breastfeeding: 600 IU (15 mcg/day)

Testing

The only way to know if you are deficient is to have your doctor perform a test, called a 25-hydroxy vitamin D test. This will tell you if, and how severely, you are deficient.

When your doctor performs a blood test and gives you the results for your vitamin D levels, keep these numbers in mind:

• 50+ equals a good level. A 25(OH)D level of >50 nmol/L is now considered the “primary goal.”
• 30–50 means you want to supplement with vitamin D, work on spending more time in the sun and/or add vitamin D foods into your diet.
• Less than 30 means you are very deficient and definitely want to take immediate action to bring those levels up.

When to see your doctor

Researchers suggest that anyone with the health conditions below should be tested for vitamin D deficiency, especially if they experience a number of deficiency symptoms described above:

• Ongoing muscle weakness
• Chronic fatigue
• Depression, especially during the winter (which can indicate seasonal depressive disorder)
• Trouble sleeping
• Anxiety
• Weak or broken bones
• Weakened immune system
• Inflammation and swelling

Frequently asked questions

What are the symptoms of low vitamin D?

Low vitamin D levels can lead to a variety of symptoms, including fatigue, bone pain, muscle weakness, mood changes and frequent illnesses. In more severe cases, vitamin D deficiency can cause bone and muscle issues, such as osteoporosis in adults and rickets in children.

What will happen if vitamin D is low?

If vitamin D levels remain low over time, it can lead to weakened bones and an increased risk of fractures. Low vitamin D can also compromise immune function, increase susceptibility to infections and contribute to mood disorders like depression.

Over the long term, vitamin D deficiency is associated with a higher risk of chronic diseases, such as cardiovascular disease and certain cancers.

How do you raise vitamin D levels quickly?

To raise vitamin D levels quickly, people can increase their exposure to sunlight, consume vitamin D-rich foods (like fatty fish, fortified dairy products and egg yolks) and take vitamin D supplements. In cases of severe deficiency, doctors may recommend high-dose vitamin D supplements for a short period under medical supervision.

What is the most common cause of vitamin D deficiency?

The most common cause of vitamin D deficiency is inadequate exposure to sunlight, which is the primary natural source of vitamin D. Factors that can limit sun exposure include living in areas with limited sunlight, using high SPF sunscreen, spending a lot of time indoors and having darker skin, which reduces the skin’s ability to produce vitamin D from sunlight.

How long does it take to fix vitamin D deficiency?

The time it takes to correct vitamin D deficiency can vary. With high-dose supplementation, vitamin D levels can improve within a few weeks to a few months, depending on the severity of the deficiency and the individual’s response to treatment.

For most people, restoring optimal levels may take about eight to 12 weeks with consistent supplementation. Regular monitoring by a healthcare provider is recommended to adjust doses as needed.

Conclusion

• Between 40% and 80% of adults in the U.S. may suffer from vitamin D deficiency symptoms, which can lead to major health issues, such as cardiovascular disease, diabetes, autoimmune disease and cancer.
• Two major causes of vitamin D deficiency symptoms are a lack of sun exposure and the use of sunscreen.
• Sunlight exposure, without sunscreen, for roughly 10 to 20 minutes per day helps your body make about 10,000 units of natural vitamin D.
• What are the symptoms of vitamin d deficiency in adults? The most common include weakness, chronic fatigue, depression, anxiety, trouble sleeping, weak bones and weak immune system.
• Vitamin D deficiency treatment usually involves vitamin D supplementation, ideally D3 (the more active form). Most adults should take between 600 and 5,000 IU daily.