Vitamin D Supplements: Do You Need Them?
A four fold rise in the incidence of rickets over the last 15 years has triggered a fresh debate about whether we need to opt for vitamin D supplements. Characterised by soft bones and a weak skeletal structure and caused due to a deficiency of vitamin D, rickets is a disease one would usually associate with the 18th century and something that we presume to have long been eliminated. Most doctors attribute this rise to the possibility that pregnant women and young children are not getting sufficient quantities of vitamin D, also known as the sunshine vitamin.
There is growing consensus on the need to use vitamin D supplements and to fortify some foods with the vitamin in order to combat the deficiency. But is that really the best way to tackle the problem? Before we explore deeper into the causes of vitamin D deficiency, let us focus on how vitamin D is synthesised by our body and how it benefits us.
What is Vitamin D?
Vitamin D is a fat soluble vitamin that consists of two major forms D2 and D3. The former is found in plants, mushrooms and the latter in animal products. It’s Vit D3 that our skin synthesises from exposure to the UVB rays of the sun and it is this form that is believed to be more effective. The synthesis of the vitamin begins with the skin and it is then processed by the liver and kidneys to produce it’s active form – calcitrol.
Benefits of Vitamin D
Vitamin D is vital for bone health as it controls the levels of calcium and phosphorous in the blood. It can either suppress the immune system to help tackle autoimmune diseases or can trigger and activate the immune system to fight infections and cancer. It is also believed to be closely associated with decreasing the risk of strokes and heart attacks. As Vitamin D is also responsible for modifying the release and response to insulin, it helps prevent diabetes. Vitamin D regulates more than 200 genes in our body and is therefore important for the health and well-being of the entire body.
Sources of vitamin D
The best source by far of vitamin D is sunlight. Other dietary sources include oily fish, cod liver oil, eggs, liver and some fortified foods. However dietary sources only provide 5-10% of the Vitamin D required by our body and the rest can only be obtained from sunlight exposure.
Vitamin D and sunlight: The cholesterol in the skin converts the UVB rays from sunlight into vitamin D. Fair skinned people need a lesser exposure to the sun as their skin absorbs more amounts of sunlight than darker skinned people and the elderly. The sun exposure depends on the UV index and the skin type. Early in the day, the sun’s rays consist of UVA which do not play any role in the synthesis of Vitamin D. The UVA instead can damage the skin leading to skin disorders and even cancer.
The UVB rays on the other hand are present in the sunshine two hours preceding and following noon time – ie between 10:30 am and 2 pm. For a fair skinned person, a 15-20 minute exposure to the sunlight between these hours, two-three times a week should complete the required quota of vitamin D.
The geographic location also determines the amount of vitamin D that can be synthesised by the skin. The local UV index needs to be 3 or more for the skin to be able to produce vitamin D from sunshine and during the winter months – between October and April, most of the UK is too far north for the sun to have enough UVB rays to make vitamin D, thus explaining why the symptoms of vitamin D deficiency soar in these months.
Is Vitamin D deficiency very common?
Recent studies have revealed that more than half of the adult population in the UK have a deficiency of the vitamin in varying degrees with its severity peaking in the winter months. People of South Asian origin in the UK are more susceptible as their darker skin absorbs lower amounts of sunshine – the very factor which is not as abundant in regions that lie too high in the northern or two low in the southern hemisphere.
Causes of Vitamin D deficiency
The main causes of vitamin D deficiency are:-
- Lack of sunlight
- Inadequate intake of foods rich in vitamin D
- Old age
Another perspective to the problem
Rather than blindly resorting to vitamin D supplements to get rid of the deficiency, maybe we need to understand the root cause of this problem.
The recent tendency to demonise cholesterol may have become an underlying cause of the recent spurt in incidences of vitamin D deficiency. It is the cholesterol in the skin that is synthesised by sunshine to manufacture Vit D. Much obsessed that we as a society have become about restricting our fat intake to “control” our cholesterol levels, we have completely overlooked this vital function of cholesterol. As long as we do not open our minds to the fact that fat too is an essential nutrient, we will suffer from an impaired ability to make vitamin D.
Vitamin D works with calcium and phosphorous to enable maximum absorption and impart maximum health benefits. These are usually found in good measure in meat, eggs and dairy products, the very foods that seem to be fashionable to shun nowadays. Ensuring an intake of these foods would do much in reducing the susceptibility to vitamin D deficiency.
It could therefore be a possibility that rickets has returned due to the following reasons attributed to warped twentieth century diktats :-
- Lower levels of cholesterol
- Lesser intake of dietary fat
- The tendency to cover up with clothing/sunscreen creams before going out into the sun
The solution therefore is not as simple as taking vitamin D supplements, which are but a temporary recourse. In order to tackle vitamin D deficiency, we need to do a rethink on seemingly established truths from a different perspective. Fortified margarine and cereals are a poor replacement for butter, eggs and dairy products which are natural sources of the nutrient. Rather than resorting to fake foods like infant formula, babies should be fed on breast milk and real, fresh food.
During the winter months, when sunshine is in short supply, we can replenish vitamin D through our diets. Sardines and other oily fish, dairy products, eggs and meat are an invaluable source of vitamin D and can help us maintain optimal levels of the nutrient even in the winter months.
The bottom line is clear. Although supplements and fortification of foods will help those with experience and good advice on their provisions, we need to change our perspective to fat, cholesterol and sunshine. So relish your meat and butter and bask in the sunshine whenever you can for that’s how nature meant us to be!