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Vitamin D

Vitamin D: A steroid vitamin which promotes the intestinal absorption and metabolism of calcium and phosphorus. Under normal conditions of sunlight exposure, no dietary supplementation is necessary because sunlight promotes adequate vitamin D synthesis in the skin. Deficiency can lead to bone deformity (rickets) in children and bone weakness (osteomalacia) in adults.

Vitamin D structure.jfif

Vitamin D is available to the body from eggs, fish, and dairy products. Active people living in sunny regions produce most of the vitamin D they need from their skin through the sunlight. In a less sunny climate, vitamin D's skin production is considerably reduced in the winter months, especially among the elderly and the housebound. In that population, vitamin D supplements become essential.


Vitamin D plays numerous roles in the body, from supporting a productive immune and nervous system to absorbing calcium and promoting healthy bone growth. It also helps to regulate mood. 


Healthy bones, calcium often comes to mind. Calcium is the major component in bone health and increasing bone mineral density, but do not overlook the importance of vitamin D. Previous research has shown that vitamin D is a powerful stimulator of calcium deposits in bones, making them stronger and healthier (Naeem, 2010). If the body is not getting sufficient vitamin D, the body begins to slow depositing calcium into bones, eventually drawing calcium out from the bones back into the bloodstream, which is dangerous! Over time, this constant deposit and withdrawal cycle will make bones weak and at high risk for fractures (Ooms et al., 1995).


Vitamin D supplementation could be interfering with strength gains if not properly regulated. Research published in the Iranian Journal of Public Health in 2010 reported that over 70 per cent of men ages 20-29 had some vitamin D deficiency (Rahnavard 2010).


Olympic weightlifters should be supplementing Vitamin D as it is vital if the body is not currently getting sufficient vitamin D. As bones are weaker which could lead to stress fractures when lifting, plus Vitamin d will help with recovery as it assists the nervous system with production.

Deficiency of  Vitamin D

Who is at risk of a vitamin D deficiency?

The NHS state that you are more likely to experience low vitamin D if you do not get enough sun exposure. This may be because you are housebound due to illness or frailty, live in a care home, work night shifts, or live in a place that does not get much sun.

Additionally, you are more at risk if you have dark skin, e.g. you are of African or South Asian descent. People with darker skin need to spend more time in the sun to stimulate adequate vitamin D production. Sun exposure aside, you may be more prone to a deficiency if you follow a vegan diet. This is because most food sources rich in vitamin D (e.g. oily fish, egg yolks) are not suitable for vegans.


Symptoms of vitamin D deficiency

Low vitamin D symptoms include the following:

Regularly getting sick

Having acceptable vitamin D levels in the body can help maintain the immune system, meaning you can fight off common infections such as colds or the flu. If you notice that you are regularly becoming unwell, this could be a sign that you are not getting enough vitamin D.

Fatigue and tiredness

Feeling very tired, to the point of exhaustion, is a common symptom of vitamin D deficiency.

Bone and lower back pain

Because vitamin D helps the body maintain bone health, a deficiency can lead to bones' pain. This is commonly felt as pain in the lower back.

Muscle aches and pain

In addition to bone and back pain, low vitamin D can also lead to aches and pains in the muscles.


Are there any long term effects of low vitamin D?

Yes. In the long term, severe vitamin D deficiency may lead to chronic health problems. In children and adults, low vitamin D can cause bone deformities – in children; it can cause rickets. In contrast, it can cause a similar condition known as osteomalacia (soft bones) in adults.

The NHS advises people during the autumn and winter months in the UK due to daylight changes to consider taking 10mcg of vitamin D each day. Sunlight is our primary “source” of vitamin D, particularly during the spring and summer. When the UVB rays in sunlight make contact with the skin, the body is stimulated to produce vitamin D. If it is likely, you are going to be inside most of the day due to lifestyle or seasonal changes it can make it hard to achieve the recommended amount and can lead to a deficiency.

Why do we need vitamin D?

Vitamin D is a vital nutrient that our body needs to maintain good health. Though our bodies can produce it via sun exposure, we can also consume it in certain foods such as oily fish and egg yolks.

Bone health

Having the correct vitamin D levels in the body is associated with good bone health and your immune system. This is because vitamin D helps the body absorb and reclaim calcium that would otherwise be excreted.

Regulates calcium and phosphate in the body

Vitamin D also regulates levels of phosphate, another mineral that contributes to good bone health. Both calcium and phosphate contribute more widely to the health of the teeth and muscles.


Images from Wix 

Naeem, Z. (2010). Vitamin d deficiency- an ignored epidemic. International journal of health sciences, 4(1), pp.V–VI. ‌

Ooms, M.E., Roos, J.C., Bezemer, P.D., van der Vijgh, W.J., Bouter, L.M. and Lips, P. (1995). Prevention of bone loss by vitamin D supplementation in elderly women: a randomized double-blind trial. The Journal of Clinical Endocrinology & Metabolism, 80(4), p.1052–1058. 

Rahnavard, Z., Eybpoosh, S., Homami, M.R., Meybodi, H.A., Azemati, B., Heshmat, R. and Larijani, B. (2010). Vitamin d deficiency in healthy male population: results of the Iranian multi- centre osteoporosis study. Iranian journal of public health, 39(3), p.45–52. 

Saguna Kenth (2020). Vitamin D deficiency and low vitamin D symptoms. LloydsPharmacy. Available at:


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