A recent nutrition survey held in Malaysia unveiled some unexpected results – almost half the children (47·5%) surveyed had vitamin D insufficiency. The Nutrition Survey of Malaysian Children is part of the South East Asian Nutrition Surveys (SEANUTS), which is a multicentre study that was conducted in four countries, namely Indonesia, Malaysia, Thailand and Vietnam. SEANUTS was carried out to comprehensively assess the nutritional status of children between the ages of six months and 12 years.
This situation where close to half of Malaysian children has insufficient vitamin D is very worrying. This is because vitamin D has several critical roles to play in the healthy growth and development of your child. The largest role that is attributed to this vitamin is how it regulates the body’s calcium and phosphate levels (both are important for healthy bones and teeth). Children with insufficient vitamin D face the risk of developing bone deformities such as rickets, while adults run the risk of osteomalacia (characterised by bone pain and tenderness).
Vitamin D also plays a role in regulating the body’s immune and neuromuscular system. Research has shown that vitamin D boosts your body’s immune system with better resistance to chronic diseases and improved immune response. Conversely, recent studies have shown that vitamin D deficiency is linked to an increased susceptibility to infection and a general vulnerability to autoimmune diseases such as multiple sclerosis (MS), rheumatoid arthritis (RA), diabetes mellitus (DM), and systemic lupus erythematosus (SLE).
There are several factors that influence how much of a nutrient is used, stored, or excreted, namely:
- Nutrient components of food, chemical form of the nutrient.
- Gender, age, nutrient status and life stage (e.g. pregnancy).
- Macronutrients – carbohydrates, proteins, fats (high ingestion rate of > 90%).
- Micronutrients – vitamins and minerals (varies widely in how much is absorbed and utilised).
- Excess intake of one mineral can influence the absorption and metabolism of other minerals.
Sources of Vitamin D
So where can you get this essential vitamin from? For starters, your body can make vitamin D by itself! This happens when your skin is exposed to enough sunlight, but only if no sunscreen is used. Normally, around 30 minutes of sun exposure to the face and arms will provide you with your body’s daily vitamin D requirement.
However, only exposure to UVB light at specific wavelength of 290–320 nanometres will work. The amount of vitamin D that is synthesised is also highly dependent on factors such as:
- how much skin is exposed to the sun.
- skin colour (i.e. lighter skin requires less sun exposure compared to darker skin, which requires more sun exposure).
- type of sun exposure (i.e. if the sun is completely covered by clouds, the UVB received can be reduced by as much as half, while staying in any kind of shade reduces the received UVB by as much as 60%.
Take note that the UVB light your skin needs to produce vitamin D does not penetrate glass – staying exposed to sunshine through a window while in a car/indoors will not work.
Unfortunately, the other health risks of exposure to UV rays means that not only is this not a viable solution, many of us do not get enough sun exposure to synthesise sufficient amounts of vitamin D. Therefore, consumption of food with high amount of vitamin D is important. Natural food sources of vitamin D include:
Other than these natural sources of vitamin D, many foods are fortified with vitamin D nowadays, such as cereals, breads, margarine, and drinks such as milk and orange juice.
A ‘Quick-Fix’ Not Always the Right Answer
Another option for getting sufficient vitamin D is from supplements. However, please check with your doctor before doing so as too much vitamin D can cause various health problems. Also called ‘vitamin D toxicity’, this condition has been linked with anorexia, weight loss, polyuria, and heart arrhythmias. In more severe cases, it can cause elevated levels of calcium in your blood – this can cause vascular/tissue calcification, which can damage your cardiovascular system and kidneys.
Another factor that needs to be considered is the possibility of interaction between vitamin D supplements and any medications your child may be taking. Certain corticosteroid medications (e.g. prednisone, prescribed to reduce inflammation) may cause reduced calcium absorption and lower his body’s metabolism of vitamin D.
The best option is still to ensure that your child gets his vitamin D from sufficient sun exposure (a good method is to play outdoor sports/games). If he is unable to get enough sun exposure, ensure that he eats nutritious foods in adequate amounts. It is far better to eat more foods that are rich in vitamin D in order to ensure that your body gets enough of it, rather than rely on supplements.
An educational collaboration with Nutrition Society of Malaysia.