With the majority of the population in Singapore staying indoors for much of 2020 (and into 2021) due to the pandemic, it’s not a surprise that a lot of people had vitamin D deficiencies – a condition that can come about when we don’t have enough exposure to the sun. Even before the pandemic, a 2019 study found that a prevalence of indoor workers who were vitamin D deficient was 32.9%. This was no different 10 years ago, when a 2010 data from the National Health survey found that 40% of Singaporeans with vitamin D deficiency.
The body needs vitamin D to absorb calcium for healthy bones. What’s more, it’s also found that people with low levels of vitamin D have significantly higher rates of virtually every health issues out there: cancer, diabetes, heart attack, stroke, and more. In short, vitamin D is crucial for our immune support as well as a whole host of benefits.
Sunlight is the best source of vitamin D, and more
Your skin makes vitamin D with the help of sunlight, and it can be quite difficult to obtain in sufficient quantities through diet alone. But one more benefit from the sun is the fact that it triggers the release of nitric oxide from your skin – it’s a huge reservoir of the stuff – into your bloodstream. Nitric oxide is a molecule produced in your body that dilates blood vessels and lowers blood pressure.
In addition, being in the warm sun means your peripheral blood vessels will dilate to allow more blood to pass close to the skin’s surface to shed heat and keep you cool. These dilated blood vessels make it easier for the heart to pump blood, thus lowering your blood pressure.
Research indicates sunshine regulates your circadian rhythm, so an hour of natural light in the morning will help you sleep better because it tells your body when to increase and decrease your melatonin levels.
Last but not least, being in the sunshine improves your mood as it boosts your body’s level of serotonin – a chemical that improves your mood and helps you stay calm and focused. A study reported that vitamin D deficiency may also play a role in depression and possibly other mental disorders, while another study reported that sunlight exposure also increased cognitive functions, especially those aged 45 and above.
Supplements don’t necessarily work
A newly published study in the Journal of the American Heart Association based on 342,000 patients found that more UV exposure is associated with lower blood pressure, not vitamin D supplements.
People in sunny Singapore not getting enough sun
A lot of us are vitamin D deficient. Despite being on a sunny island, the deficiency is partly due to common local practices, like the use of umbrellas, wearing long sleeves, and staying in the shade or indoors. Then there are those who use sunscreen, which blocks the source of vitamin D production.
Sunlight consists of both UVA (the bad stuff), which can cause premature ageing, and UVB, which triggers the synthesis of Vitamin D. So sitting near windows on in a car doesn’t get you adequate UVB exposure because virtually all commercial glass blocks UVB rays, but much of the harmful UVA radiation will penetrate the glass.
Doesn’t the sun give you skin cancer?
Yes, skin cancer is caused by sun exposure, which affects about 7.4 per 100,000 people in Singapore. There are 3 types of skin cancers: basal-cell carcinomas and squamous-cell carcinomas, or non-melanoma skin cancer (NMSC) which are the most common and are almost never fatal. Melanoma, the deadly type of skin cancer, is much rarer, accounting for only 1-3% of new skin cancers.
The prevalence of skin cancer is also affected by the ethnic background and geography – there’s a very low incidence of skin cancer observed in equatorial countries such as Singapore. Furthermore, a study in Singapore has determined that drinking caffeinated drinks (ie. coffee, tea) may reduce the risk of NMSC among Chinese.
Compare the data with this: 1 out of 3 deaths in Singapore is due to heart diseases or stroke, which is associated with high blood pressure (hypertension).
Getting adequate vitamin D
You don’t need to rush to the vitamin store to grab bottles of vitamin D – try to expose your skin to the sun instead. Experts recommend 5-10 minutes twice a week, between 10am and 3pm (a walk to lunch, maybe?). If you have darker skin, stay out in the sunshine just a little longer because the higher melanin content in dark skin inhibits vitamin D synthesis.
The daily recommended dietary allowance of vitamin D for those aged 18 and up is 2.5 mcg per day. Vitamin D can be found in eggs, liver, and oily fish, as well as fortified foods like milk, yogurt, and breakfast cereals. One large egg yolk contains 1.02mcg of vitamin D, and one 250ml cup of fortified milk contains 2.9 to 3.1 mcg.
As with anything, too much vitamin D may result in negative side-effects, including bone pain and kidney problems, as well as a build-up of calcium in the blood, which can cause nausea and vomiting, weakness, and frequent urination.
Get some sun if you’re indoors a lot
It’s worth remembering that homo sapiens have been around for 200,000 years, and have always lived outdoors until the industrial revolution. Unless you have sun sensitivity, it’s good to get out there and get a bit of sun – if you’ve been staying most hours of the day indoors, being out in the sun will alter your mood. If you’re trying to be pale for beauty, remember that the skin-whitening market is a multibillion-dollar industry.