What is vitamin D deficiency?
Insufficient levels of vitamin D in your body indicate a deficiency, which primarily affects bone and muscle health.
Vitamin D is crucial for normal bone development and maintenance, and also supports the nervous, musculoskeletal, and immune systems.
You can get vitamin D in a variety of ways, including:
Exposure to sunlight on your skin may not be sufficient for people with darker skin tones or older individuals to obtain adequate vitamin D. Additionally, geographical location can limit sunlight exposure necessary for vitamin D synthesis.
Vitamin D can also be obtained through dietary sources and supplements. Despite these various methods of obtaining vitamin D, deficiency remains a prevalent global issue.
Why is vitamin D so important?
Vitamin D is an essential nutrient for overall health, vital for regulating calcium balance in the blood and bones, as well as for bone development and maintenance. Specifically, vitamin D is necessary for utilising calcium and phosphorus to support bone growth and maintain healthy tissues.
In cases of chronic or severe vitamin D deficiency, reduced absorption of calcium and phosphorus by the intestines can lead to hypocalcemia (low blood calcium levels) and subsequent secondary hyperparathyroidism, where overactive parathyroid glands work to normalise calcium levels in the blood. These conditions can result in symptoms such as muscle weakness, cramps, fatigue, and depression.
To counterbalance low blood calcium levels caused by secondary hyperparathyroidism, the body withdraws calcium from bones, accelerating bone demineralisation (breakdown exceeding the rate of formation).
This process can lead to osteomalacia (softening of bones) in adults and rickets in children. Osteomalacia and osteoporosis increase the risk of bone fractures. Rickets specifically affects children, as their growing bones can become bowed or bent due to demineralisation.
Who does vitamin D deficiency affect?
Vitamin D deficiency can affect individuals of all ages, from infants to adults, and is more common among those with higher levels of skin melanin (darker skin tones) and individuals who regularly wear clothing covering a substantial portion of their skin. This limits exposure to sunlight, which is essential for natural vitamin D synthesis in the body.
How common is vitamin D deficiency?
Vitamin D deficiency is widespread on a global scale. Roughly 1 billion people worldwide experience vitamin D deficiency, with around 50% of the population having insufficient levels.
Symptoms and Causes - What are the signs and symptoms of vitamin D deficiency?
Severe vitamin D deficiency in children can lead to rickets, characterised by symptoms such as:
- Abnormal growth patterns resulting in bowed or bent bones.
- Muscle weakness.
- Bone pain.
- Joint deformities.
While rare, mild vitamin D deficiency in children may cause symptoms like weak, sore, or painful muscles. In adults, signs of vitamin D deficiency are less conspicuous and may include:
- Bone pain.
- Fatigue.
- Muscle weakness, aches, or cramps.
- Mood changes, such as depression.
However, some individuals with vitamin D deficiency may exhibit no signs or symptoms at all.
What causes vitamin D deficiency?
Generally, vitamin D deficiency typically stems from:
- Inadequate intake of vitamin D either from your diet or sunlight exposure.
- Impaired absorption or utilisation of vitamin D by your body.
Various factors contribute to vitamin D deficiency, such as:
- Specific medical conditions.
- Weight loss surgeries.
- Certain medications.
Additionally, various biological and environmental factors, like older age and skin melanin levels, can increase the risk of vitamin D deficiency.
How is vitamin D deficiency diagnosed?
Healthcare providers typically do not conduct routine vitamin D level assessments. However, they may recommend testing for individuals with specific medical conditions, risk factors for vitamin D deficiency, or related symptoms.
Your healthcare provider can order a blood test to measure your vitamin D levels.
How is vitamin D deficiency treated?
The objectives of managing and preventing vitamin D deficiency are aligned: achieving and sustaining an adequate level of vitamin D in your body. While increasing consumption of vitamin D-rich foods and sunlight exposure may be considered, healthcare providers often recommend vitamin D supplements.
Vitamin D is available in two forms: D2 (ergocalciferol) derived from plants, and D3 (cholecalciferol) from animals. D2 requires a prescription, whereas D3 is available over the counter. D3 is more readily absorbed by the body compared to D2. Consult your healthcare provider to determine if a vitamin D supplement is necessary and the appropriate dosage.