What Happens When the Body Does Not Get Enough Vitamin D? Symptoms and Health Effects Explained

Vitamin D is often called the “sunshine vitamin” because the body produces it when the skin is exposed to sunlight. However, modern, indoor-heavy lifestyles have limited sun exposure, making vitamin D deficiency surprisingly common. Affecting nearly 1 billion people worldwide, vitamin D deficiency can not only affect bone and muscle health, it may also increase the risk of certain medical conditions. This article explores what happens when the body doesn’t get enough vitamin D, the warning signs to watch for, and treatment options. Let’s start by understanding the importance of vitamin D for the human body.

The Role of Vitamin D in the Body

Vitamin D supports several important functions that help the body work properly on a day-to-day basis. It is not only linked to bone health but also plays a role in muscle strength, immunity, and overall balance within the body.

• Bone strength and density: Helps the body absorb calcium and phosphorus from food, which are necessary for building and maintaining strong bones and teeth.
• Muscle health: Supports muscle strength and coordination, helping reduce muscle weakness, aches, and the risk of falls.
• Immune response: Plays a role in how the immune system responds to infections, supporting the body’s ability to fight illness.
• Nerve and cell function: Contributes to proper nerve signalling and supports normal cell growth and repair.
• Calcium balance: Helps regulate calcium levels in the blood, which is important for muscle movement, nerve signals, and heart function.

People Most at Risk for Vitamin D Deficiency

Vitamin D deficiency is more common in certain groups due to lifestyle, age, or health-related factors. The people most at risk include:

• People with limited sun exposure: Those who spend most of the day indoors, work night shifts, avoid sunlight, or cover most of their skin when outdoors, which reduces natural vitamin D production.
• Older adults: Ageing skin produces less vitamin D when exposed to sunlight, and dietary intake may also be lower in this group.
• People with darker skin tones: Higher melanin levels reduce the skin’s ability to produce vitamin D, even with regular sun exposure.
• People with digestive or absorption issues: Conditions affecting the stomach or intestines can interfere with how vitamin D is absorbed from food.
• People with obesity: Vitamin D can become stored in fat tissue, reducing the amount available for use in the bloodstream.
• Pregnant and breastfeeding women: Increased nutritional needs during pregnancy and breastfeeding can raise the risk of deficiency if intake is not sufficient.

Vitamin D Deficiency Symptoms

Vitamin D deficiency can affect several parts of the body, and symptoms may vary in type and severity. Some people experience mild discomfort, while others develop more noticeable health problems over time. Being aware of these symptoms can help with early testing and timely treatment. Common symptoms include:

• Bone pain: Ongoing pain or tenderness in bones, commonly felt in the lower back, hips, or legs.
• Muscle weakness and aches: Reduced muscle strength, cramps, or persistent muscle discomfort.
• Fatigue: Feeling unusually tired or low on energy, even after rest.
• Frequent infections: Increased tendency to catch colds or other infections due to reduced immune support.
• Joint pain: Stiffness or discomfort in joints that may affect movement.
• Mood changes: Low mood, irritability, or a general feeling of low motivation.
• Delayed healing: Slower recovery from minor cuts, injuries, or illnesses.

Serious Health Conditions Caused by Vitamin D Deficiency

Long-term vitamin D deficiency does not only cause general discomfort. When levels remain low for extended periods, it can contribute to the development of several serious health conditions. Some of the medical conditions caused due to a prolonged vitamin D deficiency include:

Osteoporosis

Osteoporosis is a condition where bones become weak and brittle due to low bone density. Vitamin D deficiency reduces calcium absorption, which is essential for strong bones. This increases the risk of fractures, especially in older adults, even from minor falls or injuries.

Osteomalacia

Osteomalacia is the softening of bones in adults. Low vitamin D levels prevent proper bone mineralisation, leading to bone pain, tenderness, and muscle weakness. People may also experience difficulty walking or standing for long periods.

Rickets

Rickets occurs in children and is caused by poor bone mineralisation during growth. Deficiency can lead to delayed growth, soft and weak bones, skeletal deformities, and in severe cases, bowing of the legs or other structural abnormalities.

Frequent or Severe Infections

Vitamin D plays a key role in supporting the immune system. Deficiency can make the body more vulnerable to infections such as colds, flu, and respiratory illnesses, and recovery may be slower than usual.

Chronic Muscle Weakness

Persistent low vitamin D levels can cause ongoing muscle pain, stiffness, and weakness. This may affect mobility, making routine activities like climbing stairs or carrying objects more difficult.

Increased Risk of Falls and Fractures

The combination of weaker bones and reduced muscle strength increases the likelihood of falls and fractures, particularly in older adults. This can significantly impact quality of life and independence.

Other Potential Health Risks

Some studies suggest vitamin D deficiency may be linked to heart disease, high blood pressure, certain autoimmune conditions, and metabolic disorders, though research is ongoing. Maintaining adequate levels is considered important for overall health.

How Vitamin D Deficiency is Diagnosed

Vitamin D deficiency is diagnosed through a combination of medical evaluation, symptom review, and laboratory tests. The main steps in diagnosis include the following:

1. Medical History and Symptom Assessment

The doctor will review lifestyle habits, sun exposure, dietary intake, and any existing health conditions. Symptoms such as fatigue, bone or muscle pain, mood changes, or frequent infections are discussed. This evaluation helps identify individuals who may be at higher risk of deficiency.

2. Physical Examination

During a physical exam, doctors look for signs that may indicate vitamin D deficiency. This can include bone tenderness, skeletal deformities, muscle weakness, or difficulty in movement. Observations during this exam help guide further testing.

3. Blood Tests

The most reliable way to confirm vitamin D deficiency is through a blood test measuring 25-hydroxyvitamin D levels. This test indicates whether vitamin D levels are sufficient, insufficient, or deficient. It is a standard procedure for anyone suspected of having low vitamin D.

4. Additional Laboratory Tests

In some cases, doctors may recommend further tests to assess the impact of deficiency on the body. This can include measuring calcium, phosphate, or parathyroid hormone levels. These tests help evaluate bone health, muscle function, and overall metabolism.

5. Early Detection and Monitoring

Timely diagnosis allows for early treatment, which can prevent serious complications such as bone disorders, muscle weakness, or increased susceptibility to infections. Patients with risk factors or ongoing symptoms may require periodic monitoring to ensure vitamin D levels return to and remain within a healthy range.

How Vitamin D Deficiency is Treated

Treating vitamin D deficiency focuses on restoring adequate vitamin D levels, supporting bone and muscle health, and preventing long-term complications. The approach depends on the severity of the deficiency, age, overall health, and underlying conditions. Treatment options generally include the following:

1. Vitamin D Supplements

Supplements are the most effective way to correct deficiency. Doctors prescribe doses based on how low the vitamin D level is and individual needs. Mild deficiency may require daily doses of 600–1,000 IU, while severe deficiency may need higher doses, sometimes 50,000 IU weekly for a short period. Supplements come in various forms, including tablets, capsules, chewables, and liquid drops, suitable for both adults and children. Consistent use is important to restore and maintain healthy levels.

2. Sunlight Exposure

Sunlight helps the body produce vitamin D naturally. Exposing the face, arms, and legs to sunlight for 10–30 minutes a few times a week can improve vitamin D levels, though the exact duration depends on skin tone, geographic location, and season. People with darker skin or those living in areas with limited sunlight may need longer exposure or rely more on supplements. Proper sun exposure should be balanced with skin cancer prevention measures.

3. Dietary Sources

A diet rich in vitamin D supports treatment and long-term maintenance. Foods high in vitamin D include fatty fish such as salmon and mackerel, egg yolks, fortified dairy products, and fortified cereals. Regular inclusion of these foods in meals can help maintain healthy levels once supplementation has corrected the deficiency. Combining dietary sources with sunlight and supplements provides the best results.

4. Addressing Underlying Health Conditions

In some cases, vitamin D deficiency is linked to medical conditions that affect absorption, such as celiac disease, Crohn’s disease, or chronic kidney disease. Treating these conditions alongside supplementation is necessary for effective correction. Doctors may also recommend additional tests for calcium, phosphate, or parathyroid hormone levels to guide treatment.

Consult a General Physician at Graphic Era Hospital

Think you might have a vitamin D deficiency? Our experienced general physicians at Graphic Era Hospital can help. We’ll assess your symptoms, run the necessary tests, and create a treatment plan tailored to your needs. Whether you need dietary guidance, supplement recommendations, or ongoing monitoring, our team is here to support your health. Don’t let vitamin D deficiency hold you back from feeling your best. Call us at 1800 889 7351 today to schedule your consultation and start addressing your health concerns.