Vitamin D: Everything You Need to Know

  • 1st Revision: Sophia Bradshaw
  • 2nd Revision: Tamsin Rose
  • 3rd Revision: Emma Soopramanien

Introduction to Vitamin D

Vitamin D is important to keep bones, teeth, and muscles strong. We need around 10 micrograms (ug) of vitamin D a day. We can obtain most of this from the sun during spring and summer, but we all struggle to reach our daily limit in the autumn and winter, where nearly one-third of us do not get enough vitamin D (NHS, BBC).

Benefits of Vitamin D

Skeletal Muscle and Physical Performance

Vitamin D is said to help with muscle strength, body growth and regeneration. 

Immune System

Vitamin D can help fight off viruses and infections, including COVID-19.3 

Cancer Prevention

Studies have suggested that vitamin D can help reduce the risk of cancer. This is due to vitamin D binding to the vitamin D receptors on immune cells that regulate the expression of different genes in the body, said to reduce cancer risk. It is also necessary for cell regeneration to help with regrowth (ScienceDaily).

Mental Wellbeing

Vitamin D also plays a role in mental health. Deficiencies are found to influence depression and seasonal affective disorder, which is when your mood becomes low during shorter days. This is why making the most of the sun during the winter days is so important for your mental health.5

Vitamin D Deficiency


  • Frequently becoming ill. Vitamins boost the immune system, so not having enough increases the chances of falling ill, as the body cannot fight bacteria and viruses as effectively
  • Fatigue
  • Depression
  • Body pains
  • Wounds healing slower

Causes of a Vitamin D Deficiency

  • reduced exposure to sunlight
  • lack of foods in the diet that are rich in vitamin D
  • having more melanin: with melanin being responsible for skin pigment, darker skin colour cannot absorb sunlight (an important source of vitamin D) well
  • older age
  • having other health issues, such as thyroid disease
  • being on statins or steroids 


  • Bone loss. vitamin D plays an important role in bone strength and health, and deficiency can lead to a higher susceptibility to bone fractures. This can lead to rickets in children and soft bones.
  • Increased risk of cancer: vitamin D can help regulate cancer-causing genes. 


  • Have a blood test to check the level of Vitamin D in your blood

Increasing your Vitamin D uptake

Vitamin D and calcium supplements

Vitamin D helps to absorb calcium, so it is good to take them together to help keep bones and muscles strong and healthy.

Vitamin D rich foods

See the following link for an infographic detailing foods rich in vitamin D, such as mushrooms, eggs, and milk.7

Natural Light

This is the most accessible way to get vitamin D, especially during the summer and spring. You can acquire most of the vitamin D you need just from the sunlight. However, during autumn and winter, it is advised to take supplements and consume foods rich in vitamin D.


Vitamin D plays an important role in maintaining health. It highlights the importance of exposure to sunlight as that is the best way to get all the vitamin D we need. It is difficult in the winter, so try eating more vitamin D rich foods and even cereals fortified with vitamin D. See the following link for recipes rich in vitamin D. 

Reference List:

  3. Martineau, A.R., Jolliffe, D.A., Hooper, R.L., Greenberg, L., Aloia, J.F., Bergman, P., Dubnov-Raz, G., Esposito, S., Ganmaa, D., Ginde, A.A., Goodall, E.C., Grant, C.C., Griffiths, C.J., Janssens, W., Laaksi, I., Manaseki-Holland, S., Mauger, D., Murdoch, D.R., Neale, R., Rees, J.R., Simpson, S., Stelmach, I., Kumar, G.T., Urashima, M. and Camargo, C.A. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data, BMJ, 2017 [cited 2 Mar 2022]; 356: 6583.
  7. for-overall-wellbeing-infographic
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Mansi Patel

Bachelor of Science - BS, Biomedical Sciences, De Montfort University, England
I enjoy making science more accessible to those with non-scientific backgrounds, and this internship has given me the opportunity to do so. I am also a co-founder of a university career chat series. I enjoy spending my free time with family and friends, especially after all of these lockdowns. Cardiovascular Science is a particular interest of mine, and I find it fascinating. I really hope you enjoy reading my articles!

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