Vitamin D is commonly known as the sunshine vitamin as the human body produces vitamin D when exposed to sun, but it can be found in a variety of food sources too.

Vitamin D regulates the levels of calcium and phosphate in the body, which is important for healthy bones and teeth and it also supports the health of the brain, nervous and immune systems. Studies have shown Vitamin D may also help to regulate insulin levels, aiding management of diabetes, provide protection against cancer and prevention and treatment of inflammatory skin diseases. https://www.ncbi.nlm.nih.gov/pubmed/17326003

Who is more at risk from vitamin D deficiency:

It is estimated that 1 billion people have vitamin D deficiency or insufficiency worldwide (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4143492/, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068797/ ), common risk factors include:

• Elderly
• Dark skin.
• Overweight or obese.
• Not eating much fish or milk.
• Always using sunscreen.
• Being indoors.

What are the signs of Vitamin D deficiency?

The signs of vitamin D deficiency are very subtle and may not be noticed easily. The following are signs and symptoms of vitamin D deficiency:

• Constantly feeling ill, especially with colds or flu (https://www.ncbi.nlm.nih.gov/pubmed/24766747, https://www.ncbi.nlm.nih.gov/pubmed/27178217)
• Feeling tired and fatigued (https://www.ncbi.nlm.nih.gov/pubmed/26543719)
• Suffering back (https://www.ncbi.nlm.nih.gov/pubmed/26431139) and bone (https://www.ncbi.nlm.nih.gov/pubmed/21199469) pain
• Feeling depressed, especially in winter months (https://www.ncbi.nlm.nih.gov/pubmed/19616172)

How do I know if I am vitamin D deficient?

Symptoms of low vitamin D levels are often subtle and non-specific which make it hard to be sure it’s a deficiency and not something else.  To be sure, you can speak to your doctor and ask for a blood test or visit a Nutritional Therapist who can perform a vitamin D testing service.

How can I increase my vitamin D levels?

Sunlight is the most common and efficient source of vitamin D; it is estimated that sensible sun exposure on bare skin for 5-10 minutes 2-3 times per week allows most people to produce sufficient vitamin D.  Other ways of increasing vitamin D are by eating certain types of food (certain types of oily fish, fish oil, eggs, chicken, mushrooms) or by taking vitamin D supplements. A Nutritional Therapist can advise you on the optimum foods to include in your diet to improve vitamin D levels and also on taking supplements.

References

https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/

http://www.todaysdietitian.com/newarchives/070114p48.shtml

https://www.medicalnewstoday.com/articles/161618.php

https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/