Dr Libby answers reader questions – this week, on staying well over winter, and looking after your bones if you go dairy-free.

Question: How can I boost my immune system? I have had colds off and on in the last few months and can’t get back to feeling 100 per cent. Thanks, Sharon.

Hi Sharon, it sounds like your immune system needs some ongoing support through the winter months.

The first place to start is to ensure that you are getting enough vitamin C. Vitamin C helps to reduce inflammation and stimulate the immune system to help fight off bugs. Try increasing your intake of broccoli, kale, citrus fruit, kiwifruit and asparagus, and ensure that you are consuming vitamin C rich food each day as this is not a nutrient the body can store.

B vitamins are found in whole grains like quinoa, millet, brown rice and oats, as well as darkgreen leafy vegetables. B vitamins help to regulate the immune response and amount of antibodies produced to fight an infection. If you follow a glutenfree or grain-free diet, you may like to consider a B vitamin supplement to ensure adequate intake.

You may also like to consider using echinacea as it has been used as an immune system supporting herb for centuries. It is best-used long term and helps to modulate the amount of white blood cells present, which are what fight infection in the body. I advise that you consult with a medical herbalist for guidance with dosage and use of echinacea.

Other things to try during long periods of not feeling your best include the addition of bone broth to your diet. Simple chicken or beef stock consumed over the day helps to boost your immune system as it is full of minerals to support repair. The addition of some spices like turmeric and ginger can make it a very warming and nourishing drink to enjoy over the cooler months.

Reducing stress is critical to help your body repair. Schedule time to diaphragmatically breathe each day to help lower stress hormone production, as this signals to the body that it is safe (not in danger – which is what stress hormones can communicate), and can focus on rest and repair work – which includes good immune function.

Question: I don’t eat dairy products – how can I eat for strong bones? Thanks, Jayne.

Hi Jayne, nutrients to keep bones healthy and strong as we age include vitamins C, D and K, magnesium, calcium and boron.

Calcium is essential for building and maintaining a strong foundation of bone, while magnesium and vitamin D help the calcium we consume to be absorbed.

Vitamin K is essential for the formation of osteocalcin, which is a protein uniquely found in bones, helping to maintain overall bone strength. Vitamin C is a super star nutrient and even has a role to play in the health of our bones.

Vitamin C is critical for the production of collagen, and collagen allows the structure of bone to have enough flexibility to withstand stress (like exercise or falls) without breaking.

People choose to exclude dairy from their diets for a range of reasons, and if you do this it is important to ensure that essential bone nutrients are obtained from elsewhere in the diet.

A diet high in a variety of plant foods provides a range of nutrients.

Specific sources of calcium include tahini ( ground sesame seeds), broccoli, kale and other green leafy vegetables, almonds, salmon with edible bones, and figs, to name just a few.

Your body makes vitamin D via the action of sunlight on the skin. This will be the main way you obtain vitamin D. Foods that contain small amounts of vitamin D include organic butter (if you tolerate this), some oily fish types and eggs yolks.

Magnesium is found in nuts, seeds, brown rice, quinoa and leafy greens. Vitamin K is found most densely in dark leafy greens like kale, silverbeet, spinach and broccoli. Vitamin C rich foods like kiwi fruit, berries, citrus fruit and parsley are best enjoyed raw to preserve as much vitamin C as possible as heat can destroy some of the total vitamin C content. The advice contained in this column is not intended to be a substitute for direct, personalised advice from a health professional.