By Dr. Diksha Gupta, DO ABOM
Board-Certified Family Medicine & Osteopathic Medicine Physician • Family First Primary Care
At Family First Primary Care, serving families across Arlington, Clifton, Fairfax, Falls Church, Great Falls, McLean, Oakton, Tysons, and Vienna, Virginia, Vitamin D deficiency is one of the most frequently diagnosed conditions during routine blood work — and one of the most overlooked. Dr. Diksha Gupta, our board-certified Family Medicine physician, breaks down why low vitamin D levels affect far more than just your bones — from persistent fatigue and muscle weakness to calcium absorption and bone density — and answers the questions patients ask most: when to get a Vitamin D blood test, what a normal Vitamin D level looks like, Vitamin D3 vs. D2 supplements, and how long it actually takes to correct a deficiency.
When most people think about vitamin D, they immediately think of strong bones. While that’s certainly true, vitamin D deficiency affects much more than your skeletal system. Vitamin D plays an essential role in muscle function, immune health, calcium absorption, and overall well-being. Yet, millions of Americans have low vitamin D levels without even realizing it.
As a primary care physician, I frequently diagnose vitamin D deficiency during routine blood work. Many patients are surprised to learn that symptoms like fatigue, muscle weakness, or generalized aches may be linked to something as simple—and treatable—as low vitamin D.
In this article, we’ll discuss why vitamin D is so important, the symptoms of vitamin D deficiency, who is most at risk, when you should consider getting a vitamin D blood test, and how to safely improve your levels.
What Is Vitamin D?
Vitamin D is often called the “sunshine vitamin” because your body produces it when your skin is exposed to sunlight. Unlike most vitamins, vitamin D actually functions more like a hormone, helping regulate many important processes throughout the body.
One of vitamin D’s most important jobs is helping your body absorb calcium. Without enough vitamin D, your body cannot efficiently absorb calcium from the foods you eat, which can negatively affect bone health and lead to decreased bone density over time.
Vitamin D also supports:
- Healthy muscles
- Immune system function
- Nerve function
- Healthy bones and teeth
- Overall cellular health
What Causes Vitamin D Deficiency?
There are several reasons why someone may develop low vitamin D levels.
Common causes include:
Limited Sun Exposure
Many people spend most of their day indoors at work or school. Even during the summer, sunscreen, protective clothing, and time spent inside can reduce vitamin D production.
Age
As we get older, our skin becomes less efficient at producing vitamin D from sunlight.
Diet
Very few foods naturally contain vitamin D. Fatty fish, egg yolks, and fortified dairy products provide some vitamin D, but many people don’t consume enough through diet alone.
Certain Medical Conditions
Conditions affecting the stomach or intestines—such as celiac disease, Crohn’s disease, or after weight-loss surgery—can reduce vitamin D absorption.
Obesity
Vitamin D is stored in body fat, making it less available for use in individuals with obesity.
Vitamin D Deficiency in People with Darker Skin
One group at increased risk is individuals with darker skin tones. Vitamin D deficiency in people with darker skin is more common because higher amounts of melanin reduce the skin’s ability to produce vitamin D from sunlight.
This doesn’t mean everyone with darker skin is deficient, but it does mean they may require closer monitoring, especially if they have additional risk factors.
Symptoms of Vitamin D Deficiency
Many people have vitamin D deficiency without any obvious symptoms.
When symptoms do occur, they can be subtle and easy to blame on stress, aging, or a busy lifestyle.
Common symptoms of vitamin D deficiency include:
- Persistent fatigue
- Low energy
- Muscle weakness
- Muscle aches
- Bone pain
- Frequent illness
- Difficulty recovering after exercise
- Mood changes
- Generalized body aches
Over time, untreated deficiency can contribute to decreased bone density, increasing the risk of osteoporosis and fractures.
Why Vitamin D Matters for Bone Health
One of vitamin D’s primary roles is supporting calcium absorption.
Even if you’re getting enough calcium in your diet, your body cannot use it effectively without adequate vitamin D.
Poor calcium absorption may eventually lead to:
- Weak bones
- Increased fracture risk
- Osteopenia
- Osteoporosis
- Reduced bone density
This is why maintaining healthy vitamin D levels is such an important part of lifelong bone health.
Should I Get My Vitamin D Levels Checked?
Patients often ask, “Should I get my vitamin D levels checked?”
Routine screening isn’t necessary for everyone, but a vitamin D blood test may be appropriate if you have symptoms or certain risk factors.
You may benefit from testing if you have:
- Persistent fatigue
- Muscle weakness
- Frequent fractures
- Osteoporosis
- Chronic kidney disease
- Digestive disorders affecting absorption
- Limited sun exposure
- Darker skin
- Obesity
- A history of vitamin D deficiency
If you’re wondering where to get vitamin D levels checked, your primary care provider can order a simple blood test during your visit.
Many patients search online for a vitamin D test near me or a blood test for vitamin D near me, but your family doctor is often the best place to start. Your results can be interpreted in the context of your overall health, symptoms, and medical history.
What Is a Normal Vitamin D Level?
A common question is, “What is normal vitamin D level?”
Your vitamin D status is measured with a blood test called the 25-hydroxy vitamin D test.
While laboratories may use slightly different reference ranges, many healthcare providers generally consider:
- Less than 20 ng/mL: Deficient
- 20–29 ng/mL: Insufficient
- 30–50 ng/mL: Adequate for most adults
- Above 100 ng/mL: May increase the risk of toxicity
Your healthcare provider will interpret your results based on your individual health needs rather than relying on a single number.
Can You Get Enough Vitamin D from Sunlight Alone?
Many patients ask, “Can you get enough vitamin D from sunlight alone?”
The answer is—it depends.
Factors that influence vitamin D production include:
- Time of day
- Season
- Geographic location
- Cloud cover
- Air pollution
- Age
- Skin pigmentation
- Amount of skin exposed
While sunlight helps your body produce vitamin D, relying on sun exposure alone isn’t always practical or recommended.
Does Sunscreen Block Vitamin D Absorption?
Another common question is, “Does sunscreen block vitamin D absorption?”
Sunscreen can reduce the skin’s production of vitamin D because it blocks ultraviolet (UVB) rays. However, in real life, most people don’t apply sunscreen perfectly or cover every inch of exposed skin.
More importantly, protecting yourself from harmful UV rays significantly reduces your risk of skin cancer. For that reason, I continue to recommend regular sunscreen use while encouraging patients to obtain vitamin D through a healthy diet and supplements when appropriate.
Do I Need a Vitamin D Supplement If I Get Sun Exposure?
You may wonder, “Do I need a vitamin D supplement if I get sun exposure?”
Not necessarily.
Some people maintain healthy vitamin D levels through a combination of sunlight and diet. Others, despite spending time outdoors, remain deficient because of age, skin pigmentation, medical conditions, or lifestyle factors.
The best way to know is through a blood test rather than guessing.
Vitamin D2 vs D3 Supplements: Which Is Better?
If supplementation is recommended, patients often ask, “Vitamin D2 vs D3 supplements—which is better?”
Both forms can increase vitamin D levels.
However, most research suggests that vitamin D3 raises blood levels more effectively and maintains them longer than vitamin D2.
For this reason, many physicians recommend vitamin D3 supplements unless there is a specific reason to use vitamin D2.
Is It Safe to Take Vitamin D Every Day?
A common concern is, “Is it safe to take vitamin D every day?”
For many people, yes—but only at the appropriate dose.
The right amount depends on:
- Your current vitamin D level
- Age
- Medical history
- Bone health
- Pregnancy status
Taking excessive amounts without medical supervision can be harmful.
Always follow your healthcare provider’s recommendations rather than assuming that more is better.
How Much Vitamin D Is Too Much?
Patients often ask, “How much vitamin D is too much?”
Vitamin D is fat-soluble, meaning your body stores excess amounts rather than simply eliminating them.
Very high doses over time can cause:
- Elevated calcium levels
- Kidney stones
- Nausea
- Vomiting
- Confusion
- Kidney damage
That’s why supplements should be taken thoughtfully, especially if you’re using high-dose products purchased online.
How Long Does It Take to Correct Vitamin D Deficiency?
Another frequent question is, “How long does it take to correct vitamin D deficiency?”
The answer depends on:
- How low your levels are
- The treatment dose
- Your body’s ability to absorb vitamin D
- Whether underlying medical conditions are present
Most patients begin improving within several weeks, but it may take two to three months—or sometimes longer—for vitamin D levels to normalize. Your provider may recommend repeat blood work to ensure treatment is working.
Food Sources of Vitamin D
Although food alone often isn’t enough to correct deficiency, incorporating vitamin D-rich foods can help maintain healthy levels.
Good sources include:
- Salmon
- Tuna
- Sardines
- Egg yolks
- Fortified milk
- Fortified plant-based milk
- Fortified cereals
- Mushrooms exposed to UV light
Pairing these foods with adequate calcium intake supports healthy bones throughout life.
When Should You See Your Doctor?
Consider scheduling an appointment if you experience:
- Persistent fatigue
- Muscle weakness
- Bone pain
- Frequent fractures
- Ongoing low energy
- Risk factors for deficiency
If you’ve been searching for a doctor near me for low vitamin D, your primary care provider can evaluate your symptoms, order appropriate testing, and determine whether treatment is needed.
The Bottom Line
Vitamin D deficiency is common, but it doesn’t have to go unnoticed. Because symptoms can be subtle, many people live with low vitamin D levels for months—or even years—before they’re diagnosed. Fortunately, a simple blood test can identify the problem, and treatment is often straightforward.
Maintaining healthy vitamin D levels supports bone health, improves calcium absorption, helps preserve bone density, and may reduce symptoms such as fatigue and muscle weakness. Whether you need a vitamin D blood test, dietary guidance, or supplementation, partnering with your primary care physician is the best way to develop a plan that’s tailored to your individual needs.
At FamilyFirst Primary Care, we’re committed to helping you stay healthy through prevention, education, and personalized care. If you’re experiencing symptoms of vitamin D deficiency or wondering whether your levels should be checked, we’d be happy to help you take the next step toward better health.
ABOUT THE AUTHOR
Dr. Diksha Gupta, DO ABOM | Family First Primary Care, Fairfax, Virginia
Serving Arlington, Clifton, Fairfax, Falls Church, Great Falls, McLean, Oakton, Tysons & Vienna, VA
Dr. Diksha Gupta is a Fairfax, Virginia native and a passionate healthcare provider, delighted to offer her services to the NOVA region.
Dr. Gupta’s Credentials:
- Undergraduate: George Washington University
- Master’s: Interdisciplinary Science, Touro College of Osteopathic Medicine
- Medical School: Touro College of Osteopathic Medicine
- Residency: Virtua Health (Chief Resident)
- Board Certifications: American Board of Family Medicine (ABFM), American Board of Obesity Medicine (ABOM)
