Vitamin D deficiency: Causes, Symptoms & Treatment

Vitamin D helps the body use calcium and phosphorous. It is therefore essential for the growth of strong bones and healthy muscle. Vitamin D can also support the immune system. Vitamin D is made by the body when the skin is exposed to ultraviolet B (UVB) rays from sunlight. Most foods contain very little vitamin D, so without regular exposure to sunlight, the body will not produce adequate levels of vitamin D.

Vitamin D has been the centre of significant media attention in recent months, with the re-emergence of rickets in areas of the Africa. As there are not always obvious symptoms, a vitamin D deficiency can often go unnoticed. Vitamin D supplements are popular for people of all ages, especially during the colder months when there is limited exposure to natural sunlight.

Who is at risk of a vitamin D deficiency?

A vitamin D deficiency can pose various health risks. Commonly, it can increase the risk of cardiovascular disease or cognitive impairment, and may contribute to type 2 diabetes, hypertension, or multiple sclerosis. A severe deficiency can cause serious conditions such as rickets (in children) and osteomalacia (in adults). There are certain groups of people who are more at risk of a vitamin D deficiency, including:

• Limited exposure to sunlight – in countries like the UK ensuring your body receives adequate exposure to natural sunlight can be hard at certain times of year. A deficiency commonly affects those who spend less time outdoors.
• Dark skin – dark skin contains higher levels of melanin, which acts as a natural sunscreen. This slows down the body’s production of vitamin D in response to sunlight.
• Pregnancy – pregnant women are advised to take a vitamin D supplement daily for the duration of the pregnancy. Vitamin D supports the healthy growth and development of the foetus.
• Young children – many infant formulas are fortified with healthy levels of vitamin D. Vitamin D is essential during periods of growth to build strong bones and muscles.
• Adults over the age of 65 – over time the body’s production of vitamin D reduces. This may be related to the fact that often, participation in outdoor activities also decreases with age.
• Restricted diets – weight loss diets or restricted diets can cause a prolonged lack of vitamin D in the diet. However, with careful consideration and planning these diets can meet nutritional requirements.
• Overweight – vitamin D is removed from the blood by fat cells. Being overweight can result in too much vitamin D being removed from the blood.

Are there any symptoms?

A vitamin D deficiency does not always cause any symptoms. Often, the first sign can be a bone break or fracture. Other people may experience tiredness or general aches and pains.

In children, a vitamin D deficiency can lead to soft bones and poor growth (in particular height). This can also cause curves to form in the legs (bow-legged) and late teething. More severe cases may result in muscle pains, spasms or breathing difficulties.

How can I treat a vitamin D deficiency?

Although everyone needs vitamin D on a daily basis, if you are in one of the ‘at risk’ groups you may require higher levels. If you suspect you have low vitamin D levels ask your GP to take a blood test for vitamin D.

Try to get outdoors as much as possible. However, it is important to exercise caution as prolonged exposure to sunlight can be damaging for skin. It is possible to replenish vitamin D stores through diet and supplementation. The levels required will depend on age and the severity of the deficiency. Small amounts of vitamin D can be found in certain foods and drinks, such as milk, egg yolk, and liver.

Vitamin D supplements are popular in the UK, especially during the winter months.Cod liver oil supplements are also a good source of vitamin D, and offer the added benefits of vitamin A and the essential fatty acids EPA and DHA.