Vitamin D Deficiency: Causes, Symptoms, Treatment, and Prevention

Your body can naturally produce vitamin D when sunlight hits the skin, which is why it is widely known as the sunshine vitamin. Sadly, a lack of vitamin D is among the most widespread nutritional deficiencies across the globe. Remember that Vitamin D deficiency symptoms may vary from person to person, often affecting different body parts and overall well-being. Spotting these signs early is crucial for preventing long-term complications and maintaining optimal body function.

Causes

While no single cause for deficiency exists, the overall risk could also be higher due to certain underlying conditions or lifestyle factors. A number of the most common risk factors for vitamin D deficiency are:

• Having dark skin
• Being older
• Having an overweight or obese
• Not eating much fish or dairy
• Living far away from the equator or in regions with little sunlight year-round
• Staying or working indoors
• Working overnight shifts
• Having a chronic renal disorder
• Having gastric bypass surgery

Medical Conditions That May Lead to Vitamin D Deficiency

Vitamin D deficiency can occur when certain medical conditions affect absorption, storage, or activation of the vitamin in the body.

Digestive disorders: Conditions such as cystic fibrosis, Crohn’s disease, and celiac disease can limit the intestines’ ability to absorb vitamin D effectively from food and supplements.

Excess body weight: People with obesity may have lower circulating vitamin D levels because fat tissue can trap the vitamin and reduce its availability in the bloodstream.

Liver and kidney problems: The liver and kidneys help convert vitamin D into its active form. Diseases affecting these organs can disrupt this process and result in low active vitamin D levels.

Symptoms

A deficiency in vitamin D may present as muscle weakness and aching bones. However, for many people, the signs are subtle. Low vitamin D can pose health risks that show no symptoms

Frequent Illness or Infection

Vitamin D plays a necessary role in strengthening the immune system and helps the body defend itself against viral and bacterial infections. This is because vitamin D directly interacts with the cells responsible for addressing infection.

Hair Loss

Several foods and nutrients can influence the health and growth of your hair. While stress may be a common explanation for hair loss, severe hair loss could also result from a disease or nutrient deficiency. Studies indicate that individuals with this condition tend to have lower vitamin D levels, which are linked to increased severity of hair loss.

Anxiety

Vitamin D deficiency triggers anxiety in people. A review found that individuals with anxiety and depression had reduced levels of calcidiol, a form of vitamin D.

Muscle Pain

Pinpointing the exact reason for muscle pain can be tricky, though studies suggest that low vitamin D levels might play a role.

Other causes include

• Bone loss
• Impaired wound healing
• Bone and back pain
• Fatigue and tiredness
• Depression

Why is Vitamin D So Important?

Vitamin D is crucial for overall health, particularly in maintaining strong bones and a well-functioning body. Here are some key points why vitamin D is crucial:

• Supports Bone Health – Vitamin D helps regulate calcium and phosphorus levels, which are vital for building and maintaining strong bones.
• Enhances Calcium Absorption – It enables the body to effectively absorb calcium from the intestines, preventing deficiencies that can weaken bones.
• Prevents Bone Disorders – Chronic vitamin D deficiency can lead to conditions like:
  • Osteomalacia (soft bones) in adults
  • Rickets (weak, deformed bones) in children
  • Osteoporosis, which increases the risk of fractures
• Balances Blood Calcium Levels – In cases of deficiency, the body pulls calcium from bones, leading to accelerated bone demineralization and increased fracture risk.
• Prevents Hormonal Imbalances – Deficiency can trigger secondary hyperparathyroidism, where overactive parathyroid glands try to compensate for low calcium, causing further complications.
• Reduces Risk of Hypocalcemia – Low vitamin D levels can cause hypocalcemia (low blood calcium), leading to symptoms such as leg cramps, fatigue, muscle weakness, and even depression.
• Supports Overall Well-Being – Beyond bones, vitamin D plays a role in muscle strength and boosts immune function and mood regulation.

Ensuring adequate vitamin D intake through sunlight, diet, or supplements is crucial for maintaining strong bones and overall health.

Treatment

Treatment and prevention goals are to achieve and maintain adequate vitamin D levels. You may consider eating more foods that contain vitamin D and getting some sun exposure, but you may be told to take vitamin D supplements.

Vitamin D is available in two types: D2, or ergocalciferol, which is obtained from plant sources. It would be best if you had a prescription to get D2. D3 is available without a prescription. It is more easily absorbed than D2 and stays in the body for prolonged doses. Work with your doctor to determine if you need to take supplements and how much you should take.

Prevention

Treating and preventing the absence of vitamin D keeps an adequate vitamin D level within the body. Your doctor will let you know if you would require or keep taking vitamin D supplements. In that case, they will also advise you on the appropriate amount to take.

Getting some exposure to sunshine but not too much: It is vital to know exactly how much sun exposure is required isn’t clear. However, 10 to 15 minutes of sun exposure 2 to 3 times every week to the face, arms, legs or back could also be all that’s needed to soak up an appropriate amount of vitamin D.

One would need more sun exposure if they are older, have a darker complexion, and live in a northern climate.

The use of sunscreen and standing behind a window prevents vitamin D from being produced within the skin. However, it would be best if you remembered that an excessive amount of sunshine increases the chance of skin cancer and ages the skin. Therefore, taking an appropriately dosed D supplement is safer than getting routine sun exposure.

Foods to Eat to Increase Vitamin D

Eating vitamin D–rich foods can help improve your vitamin D levels and support bone strength, immunity, and overall health. Since only a few foods naturally contain vitamin D, including a mix of natural and fortified foods in your diet is important.

Natural Sources of Vitamin D

Some foods naturally provide vitamin D and should be included regularly:

• Fatty fish such as salmon, tuna, mackerel, sardines, and trout
• Cod liver oil and fish liver
• Egg yolks
• Beef liver
• Mushrooms exposed to sunlight

Fortified Foods

Several commonly consumed foods are enriched with vitamin D to help support your daily requirements.

• Milk and dairy products like yogurt and cheese
• Plant-based milk such as soy, almond, and oat milk
• Breakfast cereals and oatmeal
• Fortified orange juice

Including these foods in your daily meals can help maintain healthy vitamin D levels. Combining a balanced diet with safe sun exposure may further improve vitamin D status. If dietary intake is not enough, a healthcare provider may recommend supplements based on your needs.

Frequently Asked Questions