Vitamin D is a steroid hormone. It differs from other vitamins as it is produced within the body as well as being obtained from dietary sources.
Where do I get vitamin D from?
It can be found in fish liver oils (such as cod liver oil), fatty wild fish such as salmon, mackerel, tuna, sardines and herring, fortified foods (such as cereals) and egg yolks. However, only about 10% of our vitamin D intake comes from food sources, so it is nearly impossible to get adequate amounts of vitamin D from diet alone.
Exposure to sunlight is the most reliable way to generate vitamin D in your body; it is produced by the skin in response to exposure to ultraviolet (UV) radiation. It is possible to generate 20,000 units of vitamin D following only 20 minutes of sun exposure without suntan lotion. It is also found in some food sources.
What does vitamin D do?
Like all hormones, vitamin D is involved in the production of enzymes and proteins within the body, which are crucial for preserving health and preventing disease. It improves muscle strength and strengthens bone. It also has anti-inflammatory effects, aids the action of insulin within the body and has anti-cancer properties.
Because of its vast assortment of benefits, maintaining optimal levels of vitamin D is crucial for good health. Vitamin D deficiency has been linked with many of the diseases of modern society.
Why is it important to get enough vitamin D?
Vitamin D deficiency is rarely considered to be a problem in the modern world. However, it remains a common deficiency in many children and adults. Worldwide, it
is estimated that the epidemic of vitamin D deficiency affects one billion people.
Before birth and during childhood, vitamin D deficiency can cause slowed growth and skeletal deformities and may increase the risk of fractures later in life. Vitamin D helps your bones absorb calcium, which keeps them healthy and strong. In adults, vitamin D deficiency has been linked to muscle weakness and play a role in many major diseases, including osteoporosis and osteopenia, many types of cancer, depression, heart disease and heart failure, obesity, diabetes, multiple sclerosis, rheumatoid arthritis, sexual health and infertility, Parkinson’s, depression, Alzheimer’s and chronic fatigue syndrome.
Gwyneth Paltrow hit the headlines after revealing that she has been diagnosed with the early stages of Osteopenia, a bone-weakening disease that is most commonly diagnosed in elderly women. If left untreated, bones may become more brittle, leading to osteoporosis. Paltrow was confused by her doctors’ advice to get more sun in order to increase her vitamin D levels, which was counterintuitive to warnings about protecting the skin from harmful UV radiation.
So how much sunshine do you need?
All living things need sun; the important factor is getting the right balance. In the last few years, numerous studies have shown that modest sunlight exposure may actually be beneficial; helping the body to manufacture the adequate levels of vitamin D it needs to keep bones healthy and protect against a range of health problems, including skin cancer. However, excessive sun exposure can cause melanoma and skin ageing.
As a general rule, if you are not vitamin D deficient, about 20 minutes of sun exposure a day (without sun cream) is sufficient. It doesn’t matter which part of the body you expose to the sun. All you need is a common sense when heading outdoors; make sure you do it gradually and always avoid sunburn.
Are you getting enough vitamin D?
Current UK guidance is clear on who should be taking vitamin D supplements and in what quantity. It indicates that for most adults they are completely unnecessary.
Pregnant and breastfeeding women need extra vitamin D to make sure they have enough to protect their bones and ensure that their baby grows properly. They should take 10 micrograms a day – about twice the dose found in the average multivitamin pill. Other at-risk groups, which include the elderly, the housebound and those who cover their skin for religious or cultural reasons, should also take 10 micrograms.
Signs of a vitamin D deficiency include muscle pain/weakness and bone pain; don’t let these warning signals go unanswered.
The only way to accurately ascertain whether you are vitamin D deficient is to see your GP for a blood test. It is then perfectly possible to reverse a diagnosis of vitamin D deficiency with prescribed vitamin D supplementation and controlled, moderate sun exposure. Don’t rely on food alone for your Vitamin D needs. Although irresponsible sunbathing is unquestionably harmful and precautions need to be taken, regular, moderate sun exposure is essential for good health.
A diet rich in vitamin D and calcium, regular weight-bearing exercise like jogging, walking and avoiding smoking are also key to help prevent osteopenia, osteoporosis and other associated conditions.
© Sarah West Nutrition