Vitamin D deficiency occurs when the body does not have enough vitamin D to maintain proper bone, muscle, and immune health.
Because this vitamin plays a critical role in calcium absorption and inflammation control, low levels can lead to fatigue, bone pain, weakened immunity, and a higher risk of chronic disease.
Understanding what causes vitamin D deficiency and how to test for it is essential for maintaining long-term wellness.
What Is Vitamin D Deficiency?
Vitamin D is both a nutrient and a hormone that the body produces when skin is exposed to sunlight. It helps regulate calcium and phosphate levels, which are necessary for healthy bones, teeth, and muscles.
A deficiency means your body either is not getting enough vitamin D from sunlight, diet, or supplements, or it is not converting it effectively into its active form. This can affect energy levels, immunity, and bone strength over time.
Mild deficiencies often go unnoticed, but prolonged low levels can lead to conditions such as osteoporosis, osteomalacia (soft bones in adults), and rickets in children.
What Causes Vitamin D Deficiency?
Several lifestyle, environmental, and medical factors can lead to vitamin D deficiency.
Common Causes and Risk Factors
- Limited sun exposure: Spending most of the day indoors, living in cloudy climates, or consistently wearing sunscreen reduces vitamin D production.
- Darker skin tone: Higher levels of melanin reduce the skin’s ability to make vitamin D from sunlight.
- Dietary deficiency: Few foods naturally contain vitamin D. People who do not consume fortified foods or fish are at greater risk.
- Obesity: Vitamin D can become trapped in fat tissue, making it less available for use in the body.
- Age: Older adults have thinner skin and less ability to synthesize vitamin D.
- Kidney or liver problems: These organs convert vitamin D into its active form, and disease can impair that process.
- Malabsorption conditions: Disorders like celiac disease, Crohn’s disease, or gastric bypass surgery can limit the absorption of nutrients, including vitamin D.
- Certain medications: Long-term use of steroids, anticonvulsants, or weight-loss drugs can interfere with vitamin D metabolism.
Because many of these risk factors overlap, regular testing is the best way to ensure your vitamin D levels remain in a healthy range.
Common Symptoms
Vitamin D deficiency can develop slowly and produce vague symptoms that are easy to overlook. Common signs include:
- Tiredness or low energy
- Muscle weakness or cramps
- Bone or joint pain
- Frequent illness or infections
- Low mood or depression
- Hair loss
Severe deficiency can lead to soft or brittle bones and delayed wound healing.
How to Get Tested for Vitamin D Deficiency
Testing for vitamin D deficiency is simple and involves measuring the amount of vitamin D in your blood.
Common Screening Tests
- 25-hydroxy vitamin D blood test (25(OH)D): The standard test used to measure vitamin D levels in the blood. It reflects total vitamin D from sunlight, food, and supplements.
- Calcium and phosphate tests: Sometimes used alongside vitamin D testing to assess bone and mineral balance.
- Parathyroid hormone (PTH) test: Elevated PTH can indicate a long-term deficiency affecting bone metabolism.
Take Steps to Maintain Healthy Vitamin D Levels
Maintaining proper vitamin D levels is one of the easiest ways to support your immune system, mood, and bone health.
Safe sun exposure, a balanced diet, and supplements when needed can help prevent deficiency.
Schedule your vitamin D screening near you today and take a proactive step toward improving your overall wellness.