Many Singaporeans Lack Vitamin D Despite Sunny Weather, Say Doctors
And this deficiency may negatively impact one's health
Joanne Ang was exercising at home in April last year when she slipped and fell on her yoga mat. She was taken to Ng Teng Fong General Hospital, where she learnt she had suffered a hip fracture.
“I was shocked that I had an injury as serious as a hip fracture and it was not a freak accident,” said the 32-year-old, who owns a skincare business.
She was diagnosed with osteopenia – a condition characterised by low bone mass and weak bones. The doctor told her she was deficient in vitamin D, which increases the risk of fractures.
Ang subsequently underwent an operation to insert three screws in her left hip. She was also prescribed with vitamin D and calcium supplements, which she is still taking.
Like her, many people in Singapore lack vitamin D even though there is abundant sunshine here, doctors tell The Straits Times.
A normal level of vitamin D is 30 to 100 nanograms (ng) per millilitre (ml). An insufficient level is classified as below 30ng per ml, while 10ng per ml and below is considered deficient.
Vitamin D deficiency can lead to osteoporosis, a lower immunity to infections and a higher risk of autoimmune disease, among other issues.
Earlier this month, it was reported that Temasek Foundation would provide a two-month supply of vitamin D supplements free of charge to low-income households consisting of vulnerable groups, including seniors and expectant mothers.
Commonly called the “sunshine vitamin”, vitamin D is mainly produced in the skin when it is exposed to the ultraviolet B (UVB) rays of the sun.
The vitamin is involved in calcium absorption, immune function, and protecting bone, muscle and heart health.
Dr Derek Koh, head of medical health screening at Thomson Wellth Clinic, said about 80 per cent of his clinic’s patients between the ages of 30 and 70 have low levels of, or are deficient in, vitamin D.
“Most Singaporeans are not exposed much to the sun as they are largely covered by clothes and shaded by umbrellas in the afternoon,” he said.
Dr Nitish Mishra, an endocrinologist at Singapore Medical Group’s Diabetes, Thyroid and Endocrine Clinic, also said two- thirds of his patients are vitamin D deficient.
Doctors advise people to go out in the sun to increase the absorption of vitamin D into the skin. However, this should be balanced against the sun’s effects on skin ageing and cancer.
Dr Nitish Mishra, an endocrinologist at Singapore Medical Group’s Diabetes, Thyroid and Endocrine Clinic, recommends sun exposure on arms and legs for an hour five times a week.
He suggests dividing sun exposure into three 20-minute sessions with the application of sunblock. “Sunblock creams do not completely block ultraviolet B (UVB) rays and even 5 to 10 per cent exposure of UVB rays for an hour each day may be enough for vitamin D synthesis.”
The daily recommended dietary allowance of vitamin D for those aged 18 and above is 2 1/2 micrograms. Vitamin D can be found in eggs, liver and oily fish such as salmon, sardine and mackerel. Other sources include fortified food products such as milk, soya milk, yogurt, orange juice, breakfast cereals and margarine.
Dr Derek Koh, head of medical health screening at Thomson Wellth Clinic, says people may not have time to go out into the sun. “Not many women appreciate the bronzed look and many of my male patients are professionals who wear long pants and sleeved shirts daily.”
He advises patients to take “a more practical approach” by taking a vitamin D supplement daily. People can consult a doctor before starting such a supplement or any high-dosage supplement.
Text: Amrita Kaur/The Straits Times