Vitamin D Deficiency Explained: Causes, Symptoms and Solutions

Often described as the "sunshine vitamin," Vitamin D is very crucial in human life, particularly for bone health, a healthy immune system and overall wellness. Rather surprisingly, despite abundant sunlight in most regions of the world, vitamin D deficiency has become extremely prevalent, both among adults and children.

This silent deficiency can manifest as fatigue, bone pain, low immunity and even mood changes. In this guide, we'll break down what vitamin D deficiency means, why it happens, how to recognize the signs and what you can do to correct it.

What is Vitamin D and Why is it Important?

Vitamin D is a fat-soluble vitamin that plays a critical role in:

• Calcium absorption for strong bones and teeth
• Support for the immune system in combating infections
• It regulates mood and energy levels.
• Maintaining muscles and heart health

Unlike most vitamins, vitamin D acts more like a hormone and impacts over 200 genes in the body. That's one of the reasons deficiencies can impact everything from bone density to immunity and metabolism.

How Your Body Gets Vitamin D

There are three ways your body can get vitamin D:

• Sunlight exposure: Skin manufactures vitamin D when ultraviolet rays, especially UVB, hit the skin.
• Diet: Vitamin D is found naturally in or fortified within, certain foods such as fish, eggs and fortified milk.
• Supplements: These include forms of either Vitamin D2 or D3 and are required when sunlight and diet together cannot provide the daily requirement.

However, most people either don't get enough sun or dietary vitamin D to sustain optimum levels, hence its general deficiency.

Common Causes of Vitamin D Deficiency

Even when there is abundant sunlight, there are several factors that can limit the body's production and utilization of vitamin D:

Limited Sun Exposure

People who spend most of their time indoors, use strong sunscreen or are in cities with air pollution are more likely to develop deficiency.

Darker skin tone

Melanin diminishes the skin's capacity to generate vitamin D from the sun, so a person with darker skin needs to spend longer in the sun to produce the same amount.

Aging

Older adults have thinner skin and lower levels of the enzyme needed for vitamin D synthesis.

Obesity

Vitamin D is stored in body fat. In overweight people, it can become “trapped” and less available for use.

Malabsorption Disorders

Celiac disease, Crohn's disease and cystic fibrosis are some conditions that limit fat and therefore vitamin D absorption.

Kidney or Liver Disease

Both organs convert vitamin D into its active form thus, disease in either organ can result in low levels of vitamin D.

Symptoms of Vitamin D Deficiency

Vitamin D deficiency can develop over time and symptoms are often quite nonspecific, which is why many individuals would never know they had the deficiency unless blood tests revealed it.

Common symptoms include:

• Constant fatigue or tiredness
• Bone or muscle pain
• Recurring infections or slow healing
• Hair loss
• Mood changes, including depression
• Weakness or difficulty climbing stairs
• Poor wound healing

Severe deficiency can cause rickets in children (soft, weak bones) and osteomalacia or osteoporosis in adults.

Health Risks Associated with Low Vitamin D

Vitamin D deficiency has been linked to the following chronic diseases:

• Bone loss and fractures
• Weakened immune response, more frequent colds and flu
• Type 2 diabetes
• Heart diseases and hypertension
• Autoimmune diseases such as multiple sclerosis and rheumatoid arthritis
• Mood disorders include depression and anxiety.

Recent research has also examined the association between vitamin D and COVID-19 outcomes as adequate levels may support immune resilience.

How Vitamin D Deficiency Is Diagnosed

Your doctor can diagnose deficiency with a simple blood test that measures the levels of 25-hydroxyvitamin D.

Typical ranges:

• Normal: 30-100 ng/mL
• Insufficient: 20-29 ng/mL
• Deficient: Below 20 ng/mL

If you are deficient, dietary changes, supplements or lifestyle adjustments may be suggested by your healthcare provider.

How to Correct Vitamin D Deficiency

Once diagnosed, it is quite easy to treat a vitamin D deficiency through a combination of sunlight, food and supplements.

Get Sensible Sun Exposure

Spend 15-30 minutes in direct sunlight with your arms and legs exposed at least 3-4 times a week. Early morning or late afternoon sun is ideal because of minimal exposure to harmful UV. Slightly longer exposure times may be required for people with dark skin.

Consume Vitamin D–Rich Foods

Incorporate foods like fatty fish such as salmon, mackerel, sardines and egg yolks, fortified milk, cereals, orange juice and mushrooms irradiated with UV light. Vitamin D is available from diet hence, it's a valuable addition.

Take Vitamin D Supplements

For most adults, 600-2,000 IU per day of vitamin D3 is both safe and effective. Dosage does, however, depend upon age, medical conditions and baseline levels. For severe deficiencies, higher doses may be needed as prescribed by your doctor, followed by maintenance supplementation.

Have a Healthy Weight

Losing weight can help improve your body's utilization of vitamin D because excess fat tissue can trap vitamin D.

At Prakash Hospital

Our endocrinologists and internal medicine specialists at Prakash Hospital offer comprehensive assessment and management of Vitamin D deficiency, from proper testing to tailored replacement programs, in order for patients to safely restore their levels of the vitamin. Our team also focuses on identifying underlying causes, whether it be from lifestyle, absorption issues or chronic illness, that ensure long-term bone and immune health.

Prevention Tips

It is easier to prevent vitamin D deficiency than to treat it later. Here’s how you can stay protected:

• Get regular safe sunlight exposure.
• Incorporate fortified foods into your typical daily diet.
• Stay active, exercise will help to keep both bones and muscles healthy.
• Schedule regular blood tests if you're at risk, especially in older adults or those with limited sun exposure.
• Follow your doctor's advice about supplements, do not self-dose excessively.

Conclusion

Although small in size, Vitamin D is mighty in function. From keeping your bones strong to supporting your immune system and mood, it's vital for your overall health.

Unfortunately, deficiency is common but completely preventable with the proper balance of sunlight, diet and supplementation. If you find that you've been overtired, achy or just low on energy, it's time to see about your vitamin D levels.

With proper guidance and care, restoration of health can be effectively and naturally regained.