Vitamin D is commonly known as the “sunshine vitamin,” but its importance goes far beyond maintaining healthy bones. This essential nutrient helps the body absorb calcium, which is necessary for strong bones and teeth. When vitamin D levels remain too low for a prolonged period, bones can become weak, thin and fragile, increasing the risk of problems such as rickets in children and osteoporosis in adults.
Vitamin D also plays an important role in supporting the immune system. Research has additionally explored its connection with mood, brain health and emotional well-being. Despite its many functions, vitamin D deficiency is extremely common and can remain unnoticed for a long time because many people experience few or no obvious symptoms.
Dr Saurabh Sethi, a gastroenterologist trained at AIIMS, Harvard and Stanford Universities, recently highlighted some of the early signs of vitamin D deficiency in an Instagram video titled “5 things you didn’t know about vitamin D.” He also explained how people can maintain healthy vitamin D levels.
Vitamin D Deficiency: What Are the Early Symptoms?
According to Dr Sethi, vitamin D deficiency can develop quietly. A person may have low levels for years without recognising that anything is wrong.
He explained that some of the more noticeable signs can include persistent tiredness, low mood and getting infections frequently.
Other symptoms associated with low vitamin D levels may include:
- Back or bone pain
- Muscle aches and pain
- Hair loss
- Slow wound healing
- Anxiety or depression
- Unexplained weight gain
Because these symptoms can also occur for many other reasons, they do not necessarily mean that someone has a vitamin D deficiency. Testing and medical advice can help determine whether vitamin D levels are actually low.
Can Sunlight Help Increase Vitamin D?
One of the most natural ways the body gets vitamin D is through exposure to sunlight. The skin produces vitamin D when it is exposed to UVB rays.
Dr Sethi said that around 10 to 30 minutes of midday sunlight with the arms and legs exposed may help the body produce a significant amount of vitamin D. He estimated that this could generate around 1,000–2,000 IU under suitable conditions.
However, the amount produced can vary depending on factors such as skin type, season, location, clothing, sunscreen use and the intensity of sunlight.
Which Foods Contain Vitamin D?
Diet can also contribute to vitamin D intake, although naturally occurring dietary sources are relatively limited.
Foods that contain vitamin D include:
- Fatty fish such as salmon
- Egg yolks
- Mushrooms
- Vitamin D-fortified foods
Dr Sethi pointed out that obtaining the same amount of vitamin D through food can be difficult compared with what the body can produce through sunlight exposure.
This is why sunlight is often considered an important natural source of vitamin D, while dietary options remain comparatively limited.
Are Vitamin D Supplements Necessary?
For people who are genuinely deficient, supplements can be an effective way to restore vitamin D levels. However, taking high doses without medical guidance is not advisable.
Excessive vitamin D intake can cause health problems, including an increased risk of kidney-related complications. Dr Sethi said that a daily intake of around 600–800 IU is generally considered the usual range for many adults, but stressed that individuals should consult their doctor before starting supplements.
The appropriate dose can vary depending on a person’s vitamin D levels, age, health status and other medical factors.
Why Is Vitamin D So Important?
Vitamin D supports several important functions throughout the body. It helps maintain healthy bones by assisting calcium absorption, contributes to immune function and may also have an influence on mood and brain health.
Dr Sethi emphasised that vitamin D should not be viewed simply as another vitamin. He described it as functioning more like a hormone in the body and noted that it is involved in regulating more than 200 genes.
Maintaining adequate vitamin D levels can therefore be an important part of overall health. If you experience persistent fatigue, bone or muscle discomfort, low mood or frequent infections, discussing your symptoms with a healthcare professional and considering a vitamin D test may be worthwhile.