Vitamin C boosts our immune system and protects our cells and tissues from being damaged. GERALDINE LING reports

The body’s immune system protects and keeps us healthy every day by waging a seemingly endless war against harmful bacteria, viruses and other body-harming substances.

To keep this defence system working well, it is important to boost it by feeding our body with nutrients such as vitamin C.

As the human body cannot make or store vitamin C, we need to get it from the food we eat.

Fruit and vegetables, particularly oranges, papaya, broccoli and green, leafy vegetables are rich in this
power nutrient.

In Singapore, the Health Promotion Board (HPB)
recommends a daily vitamin C intake of 30mg.

A small orange contains 40mg of vitamin C. Half a
serving, or 50g, of cooked broccoli contains 30mg of
vitamin C.

Vitamin C helps our body’s white blood cells – a vital
fighting team in the immune system – to do their job
properly, said Ms Eliza Resurreccion, a dietitian at The Nutrition Place.

The vitamin is also an antioxidant. Antioxidants work by neutralising free radicals, believed to be associated with ageing and disease. 

One study published in the American Journal Of Clinical Nutrition reported that women who had higher dietary vitamin C intakes tended to have fewer wrinkles.

Said Ms Resurreccion: “Vitamin C acts like a bodyguard, protecting our cells and tissues from being damaged.”

Besides keeping our immune system strong, vitamin C also helps in wound healing. It is needed to form collagen, an important protein that is used to make skin and scar tissue, said dietitian Natalie Soh from Peaches & Pear Nutrition Consultancy.

Vitamin C also helps in iron absorption. We need iron for energy and for the transport and storage of oxygen in the body.

However, the iron in plant foods – called non-heme iron – is less well absorbed compared to the iron found in meat, poultry and fish, called heme iron.

Non-heme iron is more sensitive than heme iron to inhibitors of iron absorption such as calcium and tannic acid found in tea and coffee. The good news? Vitamin C helps to enhance both heme and non-heme iron absorption, said Ms Soh.

The daily required intake of vitamin C can be easily met through diet alone, if one takes adequate amounts of fruit and vegetables, said dietitians.

The HPB recommends taking two servings of fruit and two servings of vegetables daily.

However, not everyone achieves this in their diets every day. For those who cannot manage to include these servings in their diet regimen, supplements may be considered, said Ms Resurreccion.

Pregnant and lactating women who require a higher vitamin C intake of 50mg daily will also benefit from
supplements if they are unable to meet this need through their diet, she said.

Most research studies have suggested that a vitamin C supplement of 100 to 300mg a day is generally safe.

However, if you do take supplements, Ms Soh cautions against a daily vitamin C intake that exceeds 1,000mg.

She said: “Taking large amounts of vitamin C may result in stomach discomfort or diarrhoea.”