Vitamin D Deficiency: 10 Signs & Symptoms

Vitamin D deficiency occurs when the body doesn’t have enough vitamin D to maintain healthy bones, muscles, and other vital functions. It can cause symptoms such as tiredness, bone pain, muscle cramps, mood changes, and, in children, rickets, which interferes with normal bone growth.

Vitamin D deficiency may be caused by limited sun exposure, low intake of vitamin D-rich foods, certain medical conditions, or some medications. It is more common in people with risk factors such as older age, chronic kidney disease, celiac disease, and other malabsorption disorders.

Vitamin D deficiency is usually confirmed with a blood test, after a healthcare provider reviews a person’s symptoms and medical history. Treatment often involves taking vitamin D supplements, increasing intake of vitamin D-rich foods, and getting enough safe sun exposure to help restore healthy vitamin D levels.

Normal levels

The reference values for vitamin D in healthy people are:

• Adequate levels: >20 ng/mL (>50 nmol/L)
• Low: 10–20 ng/mL (25–50 nmol/L)
• Very low: <10 ng/mL (<25 nmol/L)

For people at higher risk of vitamin D deficiency, such as older adults, people who are pregnant or breastfeeding, and people with rickets, osteomalacia, chronic kidney disease, or malabsorption syndromes, the recommended 25-hydroxyvitamin D levels may be between 30 and 60 ng/mL, depending on medical guidance.

Vitamin D deficiency symptoms

Vitamin D deficiency can cause:

1. Delayed growth

2. Bowed legs

3. Widening wrists and ankles

4. Delayed tooth eruption and cavities

5. Osteomalacia or osteoporosis

6. Weak bones

7. Muscle pain

8. Bone pain

9. Cramps

10. Tiredness and general malaise

Adults with vitamin D deficiency may also experience hair loss and mood changes, such as depression.

In addition, vitamin D deficiency may be related to benign paroxysmal positional vertigo (BPPV), a type of vertigo that can cause dizziness when getting up or turning over in bed, for example.

Main causes

Vitamin D deficiency is mainly caused by low intake of foods high in vitamin D, difficulty absorbing vitamin D, or limited sun exposure.

Certain health conditions can also cause vitamin D deficiency, such as:

• Kidney disease
• Liver disease
• Weight loss surgery
• Obesity
• Celiac disease
• Crohn’s disease
• Cystic fibrosis
• Short bowel syndrome

The use of some medications, such as laxatives, prednisone, phenobarbital, phenytoin, rifampin, and orlistat, can also cause vitamin D deficiency in the body.

Confirming a diagnosis

Vitamin D deficiency is usually evaluated by a primary care provider or endocrinologist, based on the person’s health history and an assessment of their signs and symptoms.

To confirm vitamin D deficiency, a healthcare provider usually orders a blood test called 25-hydroxyvitamin D. This test may be recommended for people at higher risk of vitamin D deficiency, such as older adults and people with low sun exposure, obesity, or celiac disease.

Treatment options

Treatment for vitamin D deficiency includes:

1. Diet

Vitamin D can be obtained by eating foods such as salmon, oysters, milk, eggs, and sardines.

2. Supplementation

A doctor or registered dietitian may recommend vitamin D2 or vitamin D3 supplements in capsules or drops. The dose depends on the severity of the deficiency, the person’s age, and their overall health.

According to the Endocrine Society’s 2011 clinical practice guideline, infants with vitamin D deficiency may be treated with 2,000 IU of vitamin D daily for about 6 weeks, followed by a maintenance dose of 400 to 1,000 IU per day.

For adults, treatment may include 6,000 IU daily or 50,000 IU once weekly for about 8 weeks, followed by a maintenance dose of 1,500 to 2,000 IU per day, depending on the person’s vitamin D levels and risk factors.

Possible complications

Possible complications of vitamin D deficiency include:

• Rickets in children
• Osteomalacia in adults
• Low blood calcium levels, known as hypocalcemia
• Low blood phosphate levels, called hypophosphatemia
• Osteopenia
• Osteoporosis

Although sunlight helps the body produce vitamin D, the amount of sun exposure needed varies based on factors such as skin tone, season, time of day, latitude, and the amount of skin exposed.

According to the American Academy of Dermatology, vitamin D is best obtained through foods and supplements rather than intentional sun exposure because ultraviolet (UV) radiation increases the risk of skin cancer.