Winter is high season for colds, viral infections, asthma exacerbations and the flu, but you can reduce the risk of getting sick by making sure that you and your children have optimal levels of vitamins and minerals needed for a strong immune system to fight all those winter nasties. Here are 5 steps to optimal family health this winter. 

1.  Eat a healthy diet, especially lots of vegetables and fruit 

This step is to get your vitamin C, and other immune boosting nutrients. Try to eat all the colours of the rainbow every day, or at least most: some red beets, tomatoes or berries; orange kumara, carrots or pumpkin; yellow squash, lemon, corn or peppers; green spinach, kale, peas, beans or avocado; and blue berries, blue corn, eggplant or cabbage.

Include immune enhancing vegetables, such as reishi and shitake mushrooms, which contain beta-glucans that help fight infections; also serve some berries every day, which are high in antioxidants and great for your health. I always keep a bag of organic berries in my freezer. And don’t forget to add your daily dose of spices and herbs, such as garlic, turmeric, ginger, oregano and cinnamon (which actually kill bad bacteria!).

2. Avoid sugar, or reduce wherever possible

Try to avoid sugar, as this suppresses the immune system (this of course applies to the summer as well, when we generally consume even more sugar as ice cream, lollies and soft drinks).

If you haven’t taken your family to see “That Sugar Movie” yet, reserve seats right now, or download it on Youtube, and prepare your own (colourful) popcorn at home.

The first step in reducing sugar is to cut out all fizzy drinks (apart from mineral water) and lollies. These do not add anything positive to your diet and you can achieve the same “sweet happiness moments” from fruit, fruit smoothies, or a yummy mixture of nuts and dried fruits. It may take some getting used to, but you will do yourself and your family a favour by cutting down on sugar in your diet.

If you want to sweeten herbal tea use Manuka honey, which is well known for its immune boosting effects due to its “NPA” or non peroxide activity. The higher the activity indicator (10+ for example), the stronger the honey is at killing bacteria and viruses.

2. Get your sunshine vitamin D level to optimal

Vitamin D up-regulates cathelicidin, an antimicrobial protein, which is powerful at killing bacteria, fungi, and viruses.

The optimal level is about 100-120nmol/L. Given that most children in New Zealand are vitamin D deficient in the winter (this means a level of below 50nmol/L), it is likely that your child’s vitamin D will be insufficient and they will benefit from a vitamin D supplement (or a trip to Fiji). In the winter the sun is at an angle at which it is just too weak to produce much vitamin D in our skin.

In Northern European countries children receive a daily dose of vitamin D to boost their immune system and strengthen their bones. The recommended dose varies from country to country – about 400-1000 IU per day. You can get liquid vitamin D that contains the daily dose of 400IU in just one drop.

Vitamin D can also help to fight off the winter blues or SAD – seasonal affective disorder. Even if the sun is not strong enough to produce vitamin D in the winter, it’s still very healthy to spend time playing outdoors every day – the longer the better.

keep your family healthy in winter

3. Think Zinc and selenium

Our soils in New Zealand are very low in zinc and selenium. This means even if you eat an exemplary diet, you will still not get enough zinc or selenium.

This is especially true during growth spurts, when your child needs extra amounts. If your child has white spots on his fingernails, this may be a sign of low zinc or selenium stores.

Zinc is essential for the immune system, skin healing, brain function and mood. Children with a zinc deficiency can get more frequent infections, may be irritable and can struggle with learning and attention. The RDI (recommended daily intake) for zinc varies by age from 3-14mg. You may need to take a bit more during times of high need, such as an infection or if you are deficient (for a few weeks until you have corrected the deficiency and have normal levels). You can get zinc supplements as drops, capsules, tablets or even a transdermal gel for the very young.

Selenium, a potent anti-oxidant, is vital for the immune system and the thyroid gland; it may also help to prevent certain cancers. You only need a tiny dose every day – which you can get from eating 3 Brazil nuts (or one Brazil nut for a child – of course do not give nuts to children with nut allergies!) or a liquid supplement such as Clinicians Selenium drops.

You can overdose on zinc and selenium, so keep these supplements away from children and stick to the dose recommended by your health professional.

keep your family healthy in winter

4. Feed your gut flora: Probiotics

There has been a literal explosion of interest in the microbiome, the bacteria that live in and on us.

It is clear that gut bacteria play an essential part in human health and even mood. Children who take a daily probiotic get sick less often compared to children who don’t take one.

You can get probiotics as powders or capsules or, even better, eat fermented foods that naturally contain probiotics: Kefir, sauerkraut, kimchi, tempeh, olives and pickles (yoghurt is not the best source, as it does not contains large amounts of probiotics and often contains sugar and additives).

Keep your family healthy in winter

If you take these 5 steps to optimal family health this winter, you will have a healthier winter this year. If you still get sick, you may also find that you get over the illness faster.


If you or your child gets sick with a virus there is no need to artificially lower the fever. A high temperature is the body’s way of fighting an infection, of killing the virus or bacteria, which are making you sick. If you lower this artificially by giving medicines such as Pamol, you just end up being sick for longer.

If your child has a very high temperature, do take him or her to your doctor to rule out any serious infections. If you’re dealing with a cold or viral illness, supportive measures, including the 5 steps above, and extra vitamin C plus immune boosting herbs, such as elderberry, olive leaf extract, goldenseal or Echinacea can get you back to optimal health quickly. You’ll also love Mum’s amazing cold prevention remedy.

Caution: You can overdose on zinc, selenium and vitamin D, so talk to your health professional about what dose would be appropriate for you or your child and remember to take your child to a doctor if he or she gets very sick, has a high fever or you are worried about their health.

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Dr Leila Masson MD, MPH, FRACP is a paediatrician with a Master of Public Health from Harvard and extensive training in nutrition and environmental health. She is interested in disease prevention through healthy nutrition and life style. Dr Masson’s aim is to treat the whole child and to support families on their path to better health.

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