Kekurangan Vitamin D: Tanda, Punca & Sumber Vitamin D

Vitamin D helps the body use calcium to keep bones, teeth and muscles healthy. Even in sunny Malaysia, many women are low in vitamin D because they spend most of the day indoors, avoid the midday sun or cover most of their skin. Low vitamin D may cause no symptoms, but it can lead to tiredness, bone and muscle pain, and soft bones. The Malaysian Recommended Nutrient Intakes (RNI) 2017 suggest 15 micrograms (600 IU) a day for adults aged 19 to 65. This guide explains the signs of kekurangan vitamin D, who is at risk, how much you need and the best sources.

Vitamin D untuk apa? What vitamin D does

According to the NHS, vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. MedlinePlus adds that vitamin D also has a role in the nerves, muscles and immune system.

The body gets vitamin D in three ways: from sunlight on the skin, from food and from supplements (MedlinePlus).

What vitamin D does not do (yet): the Malaysian RNI 2017 notes that a lot of research has looked at vitamin D and conditions such as diabetes, cancer, heart disease and metabolic syndrome. After reviewing the evidence, the US Institute of Medicine concluded that the link was inconsistent and inconclusive, and the RNI recommendations are based on bone health. The NHS also says there is not enough evidence to take vitamin D solely to prevent or treat COVID-19.

Tanda kekurangan vitamin D (symptoms)

Cleveland Clinic notes that low vitamin D is less obvious in adults than in children, and that you may have no symptoms at all. When there are signs, they can include:

• tiredness (fatigue);
• bone pain;
• muscle weakness, aches or cramps;
• mood changes, such as low mood.

These symptoms are common and have many other causes, such as kurang darah (anaemia) or a thyroid problem, so a blood test is needed to know whether vitamin D is the cause.

Soft bones (osteomalacia): long-term lack of vitamin D or calcium can make the bones soft. In adults this is called osteomalacia, and in children it is called rickets. The NHS lists symptoms such as:

• pain in the back, shoulders, ribs, pelvis or legs;
• swollen, painful wrists;
• difficulty climbing stairs or getting out of a chair because of weak muscles;
• tingling, cramping or twitching of the muscles;
• breaking bones more easily, especially the hips, lower back and feet.

The Malaysian RNI 2017 adds that a lack of vitamin D in adults may also contribute to osteoporosis (thin, fragile bones), which becomes more common after the menopause.

Why many Malaysian women are low in vitamin D

Malaysia is close to the equator, so you might expect everyone to have enough vitamin D. The Malaysian RNI 2017 explains why many people do not:

• many people, such as office workers and housewives, spend most of the day indoors;
• the sun's UVB rays, which help the skin make vitamin D, are strongest around midday, which is also when it is hottest, so many Malaysians avoid the sun;
• sunscreen and clothing that covers most of the skin reduce how much vitamin D the skin can make;
• darker skin makes less vitamin D from the same amount of sunlight;
• heavy cloud, smoke or smog, such as during haze, can block the UV rays that help the skin make vitamin D.

What Malaysian studies found:

The RNI 2017 notes that different studies used different cut-off levels and methods, so the numbers cannot be compared directly. But taken together, they show that low vitamin D is common among Malaysian women, especially in cities.

Who is more likely to be low in vitamin D?

Based on the NHS, MedlinePlus, Cleveland Clinic and the Malaysian RNI 2017, you are more likely to be low in vitamin D if you:

• spend most of the day indoors, for example at an office job or at home;
• usually wear clothes that cover most of your skin when you are outdoors;
• have darker skin;
• have obesity. Cleveland Clinic explains that vitamin D is stored in fat cells, so less of it is available to the body. Our guide to losing weight safely in Malaysia has practical steps;
• are older, as the skin makes less vitamin D with age;
• are pregnant or breastfeeding. The RNI 2017 notes that breast milk from mothers who are low in vitamin D contains little vitamin D, and that babies are the group most at risk, so ask your doctor or clinic nurse about vitamin D for your baby;
• have a condition that affects how the gut absorbs fat, such as Crohn's disease or coeliac disease, or have had weight-loss surgery;
• have kidney or liver disease, which reduces the body's ability to activate vitamin D (see our guides to sakit buah pinggang and hati berlemak);
• take certain medicines, such as steroids (for example prednisone), some anti-seizure medicines, rifampicin for tuberculosis or the weight-loss medicine orlistat (Cleveland Clinic).

Berapa banyak vitamin D sehari? (Malaysian RNI)

The Malaysian RNI 2017 raised the recommended intake of vitamin D from 5 micrograms to 15 micrograms a day for most ages, based on the US Institute of Medicine's 2011 review. These amounts assume you get little sun, which the RNI says fits the situation in Malaysia.

Micrograms or IU? Supplement labels may use either. 1 microgram of vitamin D equals 40 IU, so 15 micrograms is 600 IU.

Sumber vitamin D: sunlight, food and supplements

1. Sunlight

The skin makes vitamin D when sunlight falls on bare skin. The Malaysian RNI 2017 describes a local study in which exposing just the face and hands to sunlight for 30 minutes, twice a week at 11am raised vitamin D levels by about 40%. The RNI cautions that people whose skin is sensitive to sun or heat may get skin irritation.

Balance this with protecting your skin. The NHS says you cannot get too much vitamin D from sunlight, but you should cover up or protect your skin if you are out in the sun for long periods to lower the risk of skin damage and skin cancer. Avoid getting sunburnt, and see our guide to kanser kulit for sun safety tips.

2. Food

Few foods are naturally rich in vitamin D. The Malaysian RNI 2017 lists these amounts, based on US food data:

Other sources include tuna, herring and egg yolks. The RNI notes that some milk powders, cereals, bread and yoghurt in Malaysia are fortified with vitamin D on a voluntary basis, so check the label. The NHS advises avoiding liver if you are pregnant. The RNI also notes that food choices high in vitamin D are limited in Malaysia, which makes it hard to get enough from food alone. If you are vegetarian, sunlight, fortified foods and mushrooms are the main options.

3. Supplements

Vitamin D is available as a single supplement and in many multivitamins. MedlinePlus says both D2 and D3 forms raise blood levels, and that vitamin D is absorbed better when taken with a meal or snack that contains some fat. Check with your doctor or pharmacist before taking a supplement, especially if you are pregnant, take other medicines or have kidney disease, and do not go above the upper limit (see below). If your doctor finds you are deficient, follow their advice on the dose.

Vitamin D blood test

Cleveland Clinic says doctors do not usually check vitamin D levels routinely, but may test if you have symptoms, risk factors or certain medical conditions. The test measures 25-hydroxyvitamin D (25(OH)D) in your blood.

Results are reported in nmol/L or ng/mL. Labs and studies use slightly different cut-offs, but the Malaysian RNI 2017 explains that a level of about 50 nmol/L was used by the US Institute of Medicine as the target that covers nearly everyone's needs for bone health. Your doctor will explain what your result means for you.

Can you have too much vitamin D?

You cannot get too much vitamin D from sunlight (NHS), but you can from supplements. Taking too much for a long time can cause too much calcium in the blood (hypercalcaemia), which can weaken the bones and damage the kidneys and heart (NHS).

The Malaysian RNI 2017 sets these upper limits:

• adults, including pregnant and breastfeeding women: 100 micrograms (4,000 IU) a day;
• children aged 1 to 13: 100 micrograms a day;
• babies: 25 micrograms (0 to 6 months) and 37.5 micrograms (6 to 12 months) a day.

Some people with medical conditions may not be able to take as much safely (NHS). If your doctor prescribes a higher dose to treat a deficiency, follow their advice.

When to see a doctor

See a doctor if:

• you have ongoing bone pain, muscle weakness or cramps, or difficulty climbing stairs or getting up from a chair (NHS);
• you break a bone after a minor fall or knock;
• you are in a higher-risk group and want to know whether you need a test or a supplement;
• you are pregnant or breastfeeding and unsure about vitamin D for you or your baby.

In Malaysia, you can start at a klinik kesihatan or a GP. For hair-related concerns, our guide to rambut gugur explains the role of iron, vitamin D and other nutrients in hair loss. If you use vitamin D creams for psoriasis, see our psoriasis guide.

Frequently asked questions (FAQ)

Apa tanda kekurangan vitamin D (what are the symptoms of vitamin D deficiency)?

Many people with low vitamin D have no symptoms. When symptoms appear, they can include tiredness, bone pain, muscle weakness, aches or cramps, and low mood. Long-term severe deficiency can soften the bones, called osteomalacia in adults and rickets in children, causing pain in the back, hips or legs and difficulty climbing stairs. A blood test can check your level.

Vitamin D untuk apa (what does vitamin D do)?

Vitamin D helps the body control calcium and phosphate, which are needed to keep bones, teeth and muscles healthy. It also has a role in the nerves, muscles and immune system. The Malaysian Recommended Nutrient Intakes (RNI) 2017 notes that evidence for benefits beyond bone health, such as for diabetes, heart disease or cancer, is still inconsistent.

Berapa banyak vitamin D sehari (how much vitamin D do I need in Malaysia)?

The Malaysian RNI 2017 recommends 15 micrograms (600 IU) a day for adults aged 19 to 65, including pregnant and breastfeeding women, and 20 micrograms (800 IU) a day for adults over 65. These amounts assume you get little sun. Do not take more than 100 micrograms (4,000 IU) a day unless a doctor advises it.

Kenapa orang Malaysia kurang vitamin D walaupun negara panas?

Although Malaysia is sunny, many people spend most of the day indoors, avoid the midday heat, use sunscreen or wear clothing that covers most of the skin. Darker skin also makes less vitamin D from the same amount of sun. In one study of Malay adults in Kuala Lumpur, 87% of women had insufficient vitamin D, compared with 41% of men.

Makanan apa yang tinggi vitamin D (which foods are high in vitamin D)?

Few foods are naturally rich in vitamin D. The best sources are oily fish such as salmon, mackerel, sardines and tuna, egg yolks and liver. Some milk, yoghurt and cereals are fortified with vitamin D, so check the label. Oyster mushrooms contain a small amount. It is difficult to get enough from food alone.

Berapa lama perlu berjemur untuk vitamin D (how much sun do I need)?

The Malaysian RNI 2017 describes a local study in which exposing the face and hands to sunlight for 30 minutes, twice a week at 11am, raised vitamin D levels by about 40%. Take care if your skin is sensitive to sun or heat, never let your skin burn, and protect your skin if you are out in the sun for long periods.

Can I take too much vitamin D?

Yes, from supplements, but not from sunlight. Taking too much vitamin D for a long time can make calcium build up in the blood (hypercalcaemia), which can weaken the bones and damage the kidneys and heart. The Malaysian RNI 2017 sets the upper limit for adults, including pregnant and breastfeeding women, at 100 micrograms (4,000 IU) a day.

Disclaimer

This article is for general information only and is not a substitute for advice, diagnosis or treatment from a doctor. Health supplements are not intended to diagnose, treat, cure or prevent any disease.

References

• Recommended Nutrient Intakes for Malaysia 2017, Chapter 14: Vitamin D — National Coordinating Committee on Food and Nutrition, Ministry of Health Malaysia
• Vitamin D — NHS
• Rickets and osteomalacia — NHS
• Vitamin D — MedlinePlus, US National Library of Medicine
• Vitamin D deficiency — Cleveland Clinic
• Moy FM, Bulgiba A. High prevalence of vitamin D insufficiency and its association with obesity and metabolic syndrome among Malay adults in Kuala Lumpur, Malaysia. BMC Public Health. 2011;11:735.
• Nurbazlin M, et al. Effects of sun exposure on 25(OH) vitamin D concentration in urban and rural women in Malaysia. Asia Pac J Clin Nutr. 2013;22(3):391–399.