We all know vitamins and minerals are vital for keeping us healthy. But how many are there, why are they so important, and how can we make sure we’re getting the nutrition we need?
Mention vitamins and minerals and you probably have at least a rough idea of their importance to the human body. For example, you might know that fruit is rich in Vitamin C, a natural antioxidant. Or that milk contains calcium for stronger teeth and bones. But what about beyond that? Just how many are there, and what do they actually do?
Let’s start with the basics. Vitamins and minerals are essential nutrients that enable our bodies to develop and function normally – some of the raw materials for maintaining life, if you like.
Although we only need relatively tiny amounts of each vitamin and mineral on a regular basis, together they perform hundreds of different roles in our body, from strengthening our immune system to converting food into energy to repairing our cells, and much more.
Our bodies may need them, but they are unable to manufacture them in sufficient amounts on their own. Thus most vitamins and minerals can be found in the food we eat. Perhaps most importantly, failing to get them practically guarantees we’ll get sick.
The good news is, however, that we can easily achieve our daily needs by eating a balanced diet including the four main food groups of carbs, protein, fat and fibre. But enough of the generics, let’s get specific.
Vitamins are organic substances that occur naturally in many of our plant and animal foodstuffs. They are either fat-soluble or water soluble. Fat-soluble vitamins (A, D, E and K) can be stored in our body for longer, but water-soluble vitamins (C and all the Bs) cannot, and must be replaced regularly. Interestingly, the human body is also able to produce vitamins D, K and choline, more of which later.
There are 14 vitamins we need in varying daily amounts (see recommended maximum levels1 next to each):
Vitamin A (Retinoids & Carotene) – 900mcg
Essential for growth and development, immune function, red blood cell formation, reproduction, and eye health – a deficiency could cause night blindness or clouding of the corneas. So if possible be sure to include things like carrots, broccoli, spinach, kumara, dairy and eggs in your diet.
Vitamin B1 (Thiamin) – 1.2mg
Used for the conversion of food into energy and to keep your nervous system running smoothly. Avoid such diseases as beriberi by eating anything from pork, beans and pasta to nuts, sunflower seeds, whole grains and brown rice.
Vitamin B2 (Riboflavin) – 1.3mg
Again, for food into energy, growth and development and red blood cell formation.
A lack of Vitamin B2 can include symptoms such as swollen or cracked lips, so tuck into asparagus, bananas, dairy, mushrooms, seafood and more.
Vitamin B3 (Niacin) – 16mg
As well as our usual favourites of converting food into energy and nervous system health, niacin aids in cholesterol production and digestion. Low levels can manifest themselves as skin disorders, diarrhoea or other intestinal upsets. All the more reason to eat meat, seafood, nuts and whole grains, among others.
Vitamin B5 (Pantothenic acid) – 5mg
We’ll take food into energy and nerve health as a given here, but Vitamin B5 also covers hormone production and fat metabolism. Greens, mushrooms, dairy, eggs, and avocados are just some of the foods rich in it – to prevent pins and needles.
Vitamin B6 (Pyridoxine) – 1.7mg
Good for your immune and nervous system function, along with metabolism and red blood cell formation. Chickpeas, bananas, potatoes, salmon and tuna will all help you from becoming anaemic.
Vitamin B7 (Biotin) – 30cmg
Helps with your metabolism again, and also for storing energy. So avoid possible dermatitis and intestinal inflammation by eating avocados, cauliflower, eggs, raspberries, pork and salmon.
Vitamin B9 (Folic acid) – 400mcg
Folic acid is essential for DNA production, which is why doctors recommend supplements for pregnant women, to avoid birth defects. Other natural sources include sunflower seeds, leafy veges, peas, legumes and liver.
Vitamin B12 (Cobalamin) – 2.4mcg
A sticking point for vegetarians and vegans, Vitamin B12 is only contained in foods of animal origin such as meat, fish and dairy. So if you prefer a plant-based diet and want to retain a healthy nervous system, try fortified soy products or supplements.
Vitamin C (Ascorbic acid) – 90mg
Good for your bones, blood, healing, immune system and helps your body absorb iron. A lack of it can lead to scurvy and tooth decay, so eat plenty of raw fruit and veges - cooking them destroys the Vitamin C.
Vitamin D (Calciferol) – 20mcg
Essential for bone growth, hormone production and maintaining a healthy blood pressure, among other things. A lack of it may cause rickets or bone weakness. As well as eating fatty fish, eggs, liver and mushrooms, exposure to UV rays also helps your body to produce its own Vitamin D. A good reason to get outdoors more.
Vitamin E (Alpha-tocopherol) – 15mg
A good all-rounder when it comes to blood health, immune function and antioxidant activity, a dearth of Vitamin E can cause nerve and muscle damage. Thankfully almonds, eggs, nuts and leafy greens are all packed with the stuff.
Vitamin K (Phylloquinone, Menadione) – 120mcg
Blood clotting and strong bones are the two main benefits of Vitamin K, which can be found in green veges, pumpkins, figs and parsley. Bacteria in our body can also help to produce it naturally.
Choline – 550mg
Although not on everyone’s list, choline is a nutrient similar to the B family of vitamins, and important for cell growth and brain and nervous system function. It can be made in the liver, or eaten in nuts, beans, fish, veges and eggs.
Minerals on the menu
And so to minerals. Unlike vitamins, minerals are inorganic substances, essentially elements (most appear on the Periodic Table) that can be found naturally in soil and water. They’re absorbed by plants then eaten by us – either directly or via animals – and like vitamins they team up to perform all sorts of different tasks to keep us healthy.
The key role of the major minerals like sodium, potassium and chloride is to help us maintain a healthy balance of water in the body. Bones are taken care of by phosphorus, magnesium and, you guessed it, good old calcium. And sulphur does its bit for protein structure in matters such as hair, skin and nails.
Then there are the trace minerals. Although you could easily contain the amount of trace minerals in our bodies in something the size of a thimble2, they’re no less essential. For example, iron helps to ferry oxygen around our body, zinc helps your blood clot, your tongue taste and your nose smell, and copper helps to create haemoglobin in your blood.
Iodine, manganese, molybdenum, fluoride, chromium…the list of minerals for maintaining our health continues, but the key is to get the right balance. And again, that mostly comes down to diet.
Diet v supplements
In a 2009 study, around half of New Zealanders said they had taken vitamin supplements of some description in the last year, with around 30% being regular users.3 More recently those numbers are believed to have grown. Kiwis now spend over a billion dollars on supplements every year.4 But is it all worth it?
While many experts admit that taking supplements may help to boost health when our diet is lacking in some areas – for example, fish oil has been strongly linked to reducing the risk of heart disease – most trials have revealed little influence on health so far.5
The message, then, seems clear. If we eat enough fruit, veges, nuts, whole grains and fish, we’ll get all the vitamins and minerals our bodies need.