With an abundance of food options available, deciding what foods to choose can be a daily battle - and this is just to consume the right amount of macronutrients (carbohydrates, proteins and fats). Within this daily dilemma is an often-overlooked problem that also revolves around whether or not we are getting the maximum benefits from the foods that we choose to consume. This battle revolves around the subject of micronutrients - the vitamins, minerals and salts that we need to keep our bodies healthy and functional.
When we hear the phrase micronutrients, we might get confused as to whether or not this is another phenomena we haven't heard of or just a person misquoting the word macro. What we don't think of are the nutrients that we need to obtain through our food each and every day to ensure that we are working at an optimum level and fighting off risks such as; disease, fatigue, inflammation, infection and overall deficiency and its specifically associated effects.
So what are these micronutrients and what are the best food sources? Also, how much do I need every day? To answer this, we first need to look at some of the necessary vitamins, minerals and salts as stated under theAustralian Government Nutrient Reference Guidelines (ADULTS ONLY) (values will vary between genders).
Vitamin A - Retinol
Retinol is needed to maintain normal immune function, reproduction and vision. Adults need between 700 and 900 µg a day (depending on gender). Sources include: sweet potato, carrots, dark leafy vegetables and pumpkin.
Vitamin B - (Thiamin, Riboflavin, Niacin, Folate/Folic Acid, B6 and B12, Biotin and Pantothenic Acid)
The B group vitamins are extremely important for individuals on a daily basis. Collectively their role is to help release the energy from the macronutrients themselves. Individually they have very different roles. Thiamin helps regulate appetite and support metabolism, riboflavin helps keep skin healthy, niacin promotes a healthy nervous system, benefits cardiovascular health and aids with energy production. Folate promotes red blood cell health and nervous system function, B6 supports red blood cell growth; B12 further boosts red blood cell and nervous system growth. Biotin and Pantothenic Acid further promote a healthy metabolism.
Thiamin - 1.1-1.2mg/day - Pork, green leafy vegetables, whole-grains, lentils and peas
Riboflavin - 1.1-1.3mg/day - Milk, yoghurt, green leafy vegetables, chicken, fish and eggs
Niacin - 14-16mg/day - Chicken, turkey, salmon and tuna (tinned in water), legumes and whole wheat
Folate - 400µg/day - Green leafy vegetables especially spinach, whole grains as well
B6 - 1.3-1.7mg/day - Chicken, green vegetables, potatoes and bananas
B12 - 2.4µg/day - Beef and seafood
Pantothenic Acid - 4-6mg/day - Yoghurt and avocado, legumes and peas
Biotin - 25-30µg/day - Liver and egg yolks, salmon, avocado and pork
Vitamin C - Ascorbic Acid
Vitamin C is needed for the promotion of immune function, energy production, blood vessel and connective tissue maintenance as well as being a powerful antioxidant. 45mg a day is all that is needed although up to 1000mg is considered a prudent limit! Great sources include capsicum, guava, green leafy vegetables, broccoli and berries - all higher than oranges!
Needed for the production, repair and maintenance of bone immune function and to alleviate inflammation. 5-15µg/day needed (higher as individuals age). Apart from dairy (milk, yoghurt etc) high sources of vitamin D include cod liver oil, oily fish such as trout, portabello mushrooms and tofu.
Vitamin E is a powerful antioxidant and thus assists with reducing overall oxidative stress on the body. This can protect against heart disease, cancer and eye damage (macular degeneration). Too much however can lead to excessive bleeding. 7-10mg/day is sufficient. Strong sources include tofu, spinach, almonds, sunflower seeds and avocado.
Fat-soluble vitamin that is responsible for blood clotting and protein modification. 60-70µg/day. Sources include dried basil, green leafy vegetables, spring onions, chilli powder and asparagus.
Plays a vital role in healthy muscle function, nerve signalling and teeth and bone development and strength. 1000-1300mg/day is needed with older individuals needing more. Apart from dairy sources, green leafy vegetables, bok choi, tofu, broccoli, snap beans, okra and almonds are all great foods to derive your daily intake.
Plays a very important role in the regulation of thyroid hormones, which are vital for the body's metabolism. Deficiencies in iodine can lead to underactive thyroid glands and thus decreased metabolism leading to an increase in fat gain. 150µg a day is sufficient. Seaweed (depending on type) is a great source as well as cod. Baked potato with the skin, shrimp and turkey breast are also good sources.
Essential for the transport of oxygen around the body, via red blood cells. Deficiencies in iron can lead to anaemia, which can cause fatigue and body weakness. Iron deficiency is far more common in vegetarians so it's something to be very mindful of if you avoid animal products. 8-18mg/day is the recommended intake. Liver is a great source as well as red meat. Oysters, mussels and clams too. For vegetarians, nuts such as cashews, almonds, peanuts and hazelnuts are great sources as are pumpkin seeds. Spinach and other dark leafy greens are also great sources.
Essential for maintaining normal muscle and nerve function, a healthy immune system, building strong bones and even lowering stress. 320-420mg/day is needed. Great sources include dark green leafy vegetables, squash and pumpkin seeds, mackerel, green beans and lentils, avocado, dairy and even bananas! If it fits your macros, dark chocolate is very high, but not to be consumed too often!
Essential for a healthy fluid balance and thus muscle function. Deficiencies can have an effect on blood pressure as well as hydration. 2800-3800mg/day is required, with some great sources including bananas, white beans, dark leafy vegetables, baked potatoes with the skin and even yoghurt.
Similar to potassium as its role is maintaining fluid balance and hydration in the body. Recommended total is between 420-900mg/day although up to 2000mg has been seen in very active people who drink high amounts of water and sweat a lot through various activities. Most food sources are very high in sodium, so it's easily obtained and rather this is one of the few micronutrients that we need to actually decrease in our daily diets as we find that most processed foods (particularly breads and sauces) are very high in sodium already. If you find that your diet is very high in sodium, there is no need to panic! Simply look to increase your daily intake of water, and increase your daily exercising amount and that is a short term solution until you can alter your intake of food.
Essential for a strong immune system, protein synthesis, creating DNA and even maintaining a strong sense of smell. One of the best ways to protect yourself against cold and flu in the colder months of the year. 8-14mg/day is sufficient. Great sources include oysters, red meat, wheat germ, spinach, cashews and pumpkin seeds.
Factors affecting nutrient levels in the body
With all this information at hand, you can see that these micronutrients are very easily obtained through a healthy and balanced diet. However, please be aware that babies, children, teenagers and pregnant women will all require different daily intakes compared to the adult values posted. It is also important to mention that substances high in caffeine such as energy drinks, coffee and tea will also cause your body to lose a lot of these nutrients so if you are consuming such substances, be extra vigilant and be aware that you may need to alter your daily intake to match. Alcohol is another substance that can alter your body's levels of these nutrients so again, be aware of the effects!
It is important to note that these are just guidelines provided by the Australian government and may vary for each individual; so if you are unsure about any of the information, please contact an appropriate healthcare professional.