Here are 12 less obvious symptoms that may be associated with vitamin D deficiency, along with details about each.
1. Frequent Illnesses or Infections
Vitamin D plays an important role in supporting the immune system.
Possible signs:
- Frequent colds or flu
- Recurrent respiratory infections
- Slow recovery from illness
Why it happens:
Vitamin D helps immune cells recognize and respond to bacteria and viruses. Low levels may be associated with an increased risk of some infections, although many other factors also affect immunity.
2. Persistent Fatigue
Feeling tired all the time can sometimes be linked to low vitamin D.
Symptoms:
- Lack of energy
- Daytime sleepiness
- Feeling exhausted despite adequate sleep
Why it happens:
Vitamin D receptors are found throughout the body, including in muscles and the brain. Deficiency may contribute to fatigue in some people.
3. Bone Pain
Vitamin D helps the body absorb calcium, which is essential for healthy bones.
Symptoms:
- Deep aching pain in the ribs, hips, pelvis, or legs
- Tender bones
- Pain that worsens with pressure
Why it happens:
Without enough vitamin D, bones can become poorly mineralized, leading to pain and, in severe cases, osteomalacia (softening of the bones in adults).
4. Muscle Weakness and Cramps
Vitamin D is important for normal muscle function.
Symptoms:
- Difficulty climbing stairs
- Trouble standing up from a chair
- Muscle cramps
- Muscle aches
Why it happens:
Deficiency can reduce muscle strength and balance, increasing the risk of falls, particularly in older adults.
5. Mood Changes or Depression
Some studies suggest an association between low vitamin D levels and mood disorders.
Possible symptoms:
- Persistent sadness
- Low motivation
- Irritability
- Anxiety
Important note:
Depression has many possible causes. Vitamin D deficiency may be one contributing factor for some people, but it is not the sole explanation.
6. Slow Wound Healing
Cuts and wounds that take longer than usual to heal may be linked to low vitamin D.
Why it happens:
Vitamin D supports inflammation control and tissue repair, both of which are important for wound healing.
7. Hair Loss
Vitamin D may play a role in the normal growth cycle of hair follicles.
Symptoms:
- Increased hair shedding
- Thinning hair
Important note:
Hair loss is more commonly caused by genetics, hormonal changes, stress, nutritional deficiencies (such as iron), or certain medical conditions. Vitamin D deficiency is only one possible factor.
8. Back Pain
Chronic lower back pain has been associated with vitamin D deficiency in some studies.
Possible symptoms:
- Persistent lower back pain
- Stiffness
- Difficulty moving comfortably
Many other causes of back pain are more common, including muscle strain and spinal conditions.
9. Excessive Sweating (Especially on the Head)
Historically, excessive sweating—particularly in infants—has been described as a possible sign of vitamin D deficiency.
Symptoms:
- Sweaty forehead
- Night sweating
Because sweating has many possible causes, it should not be used alone to diagnose vitamin D deficiency.
10. Bone Fractures
Low vitamin D can contribute to weaker bones over time.
Possible signs:
- Stress fractures
- Fractures after minor injuries
- Reduced bone density
Vitamin D deficiency increases the risk of osteoporosis and fractures, especially in older adults.
11. Balance Problems
Poor balance may be another consequence of vitamin D deficiency because of its effects on muscle strength and coordination.
Symptoms:
- Feeling unsteady
- Increased falls
- Difficulty walking confidently
This is especially important in older adults.
12. Tingling or Generalized Body Aches
Some people report:
- Tingling sensations
- General body aches
- Diffuse muscle discomfort
These symptoms are not specific to vitamin D deficiency and may have many other causes, including nerve disorders or other vitamin deficiencies. A medical evaluation is important if these symptoms persist.
Who Is at Higher Risk?
You may be more likely to develop vitamin D deficiency if you:
- Spend little time outdoors
- Consistently use high-SPF sunscreen when outside
- Have darker skin
- Are over 65 years old
- Have obesity
- Have conditions that reduce nutrient absorption (such as coeliac disease or inflammatory bowel disease)
- Follow a diet very low in vitamin D-rich foods
Foods Rich in Vitamin D
Good dietary sources include:
- Oily fish (salmon, mackerel, sardines)
- Egg yolks
- Beef liver
- Fortified milk and plant-based drinks
- Fortified breakfast cereals
- UV-exposed mushrooms
How Is Vitamin D Deficiency Diagnosed?
The most reliable method is a blood test for 25-hydroxyvitamin D (25(OH)D). Your healthcare provider can interpret the result and recommend treatment if needed.
Treatment
Treatment depends on how low your vitamin D level is and your individual circumstances. It may include:
- Vitamin D supplements (dose recommended by a healthcare professional)
- Eating more vitamin D-rich foods
- Safe sunlight exposure where appropriate
Avoid taking high-dose vitamin D supplements without medical advice, as excessive vitamin D can lead to harmful calcium buildup in the body.
If you have ongoing bone pain, muscle weakness, repeated fractures, or persistent fatigue, it’s a good idea to discuss these symptoms with a healthcare professional, who can determine whether vitamin D deficiency or another condition may be responsible.