This is a question a friend put to me the other day, so I thought I would put together the main areas of concern and how to get around them.
Firstly, vegetarianism has been around for millions of years and there is no harm in a properly balanced vegetarian diet. However, because a child’s nutritional needs differ from that of an adult, you do need to do some planning to ensure your daughter is getting key nutrients especially as she is going through hormonal changes from being a girl to becoming a young adult, she will be menstruating and in general going through major growth and development. The nutrients of most concern for all vegetarians are protein, calcium, vitamin D, vitamin B12, iron, zinc, and omega-3 fatty acids so let’s look at how to get the best sources.
Essential to growth and development is protein
A protein’s nutritional value is measured by the quantity of essential amino acids it provides. Animal based foods (outside of meat) such as milk, eggs, and fish contain all of the essential amino acids and a considered a complete protein. For strict vegetarians plant proteins usually lack at least one amino acid and are considered incomplete protein. Vegetable sources of protein, such as beans, nuts, and whole grains, offer healthy fibre, vitamins, and minerals. Nuts are also a great source of healthy fat, protein and nutrients. To get a complete protein from vegetables you need to mix grains like brown rice with legumes peas and beans. By consuming complete protein you have all the essential animo acids that are needed for bone strength and growth.
The amount of protein required for a person, is variable and depends on body weight, age, physical activity and health condition.
Calcium plays a major role in our body in building and maintaining bones and teeth, it is also essential for muscle contraction, regulation of heart beat and clotting of blood. The recommended daily intake of calcium for young adult females is 1,200mg. Foods that are high in calcium are kelp and other seaweeds, hard cheese like cheddar, leafy green vegetables like spinach, silver beet, kale, and other good sources are nuts such as almonds, yoghurt, tofu. Kelp contains 1,093mg of calcium per 100g serving where as cows milk is 118mg per 100g. Kale contains 249mg per 100g and cheddar cheese 750mg per 100g so just ensure meals throughout the day have enough levels of calcium. Concern for not enough calcium is osteomalacia which is softening of the bones, low calcium levels also contribute to high blood pressure and osteoporosis.
Anemia through Iron and B12 deficiency
Iron deficiency is the most common cause of anemia, the high risk age group for anemia is teenage girls and pregnant women as well as elderly. Iron deficiency can be caused by inadequate dietary intake. Your red blood cells (RBC) depend on iron to transport oxygen to your body cells, when levels are low your RBC will be low and small in size. There are two forms of dietary iron ‘heme iron’ and ‘nonheme iron’. Heme iron is an iron that is bound to hemoglobin and myoglobin and is found in animal products it is the most efficient form of absorbable iron. In comparison non heme iron from plant based foods is not as easily absorbed. The recommended daily intake for Iron is 15 milligrams for females. For vegetarians the best source comes from dark green leafy vegetables, brewers yeast, dried fruits, almonds. Essential for vegetarians to enhance irons absorption is to ensure high levels of vitamin C are within your diet, Vitamin C is regarded as the most potent enhancer of Iron. Have 500 milligram of Vitamin C with each meal to ensure adequate Iron absorption. Avoid foods that inhibit Iron absorption such as coffee, tea, egg yolks, brazil nuts.
Vitamin B12 deficiency anemia is often due to a defect in absorption. For B12 to be absorbed it must be extracted from food by hydrochloric acid in your gut and bond to instrinsic factor within small intestine. Dietary lack in B12 is often associated with strict vegetarian diets, our body stores of B12 can remain normal for up to three to six years so deficiency is often not picked up for many years. Vitamin B12 deficiency can cause damage to your nerves and can affect memory and thinking, it is known to mimic Alzheimers disease in the elderly. People will often present with a smooth beefy red tounge, bleeding gums and often have diarrhoea. B12 deficiency can also cause a burning feeling in your feet . Vitamin B12 is found in foods from animals, such as meat, seafood, milk products, poultry, and eggs. The richest source is from liver. It is not in foods from plants unless it has been added to the food (fortified). Some foods, like cereals, are fortified with vitamin B12. Vegetarians can source B12 from fermented foods and brewers yeast however there is a massive amount of variation in the levels of B12 that are within brewers yeast and fermented foods and often they do not meet the body’s requirements. The best non meat source is swiss cheese, eggs, whey powder, milk and yoghurt and yeast extract spreads such as marmite outside of this a good quality B12 supplement is recommended.
Vitamin D is needed for your body to be able to absorb calcium. It can be produced in our bodies by the action of sunlight on our skin and is converted to a usable source by our liver and kidneys. Most vegetables are quite low in Vitamin D, the best source is the dark green leafy vegetables, other sources high in vitamin D are cold water fish such as salmon, mackerel. Disorder of the liver and kidney can reduce the conversion of vitamin D also low levels of estrogen and maganium can reduce vitamin D conversion and studys believe this to play a role in osteoporosis.
Adequate zinc levels are necessary for proper immune function, protein synthesis, cell growth, and thyroid gland function. It is essential for the maintenance of vision, taste and smell. During puberty there is an increased need for zinc due to increased hormone production. The recommended daily intake for zinc is 12 milligrams for women. Good sources of zinc are found in shell fish – oysters, with the best, common plant sources of zinc being from legumes, nuts, seeds, and oatmeal. Phytates, which are commonly found in plant foods, can reduce zinc absorption, and some researchers have suggested that this increases the zinc needs of vegetarians by up to 50%. Protein increases zinc absorption. Because of this, foods high in protein and zinc, such as legumes and nuts, are good food choices.
Omega 3 fatty acids
Omega 3 fatty acids play a role in every cell in the body. Omega 3 makes up cell membranes, keeps the nervous system functioning, keeps cholesterol levels in check, and starves off inflammation.
The best sources of Omega 3 outside of fish can be found in flaxseeds they are rich in fiber, which aids digestion, and are great for a healthy heart. Chia seeds also provide a healthy dose of omega-3 as well as calcium, and hemp seeds are loaded with protein and omega-3. Other seeds like sunflower, safflower and pumpkin have omega-3, but they have it in small ratios. Berries are not only good sources of antioxidants, vitamins and minerals, but they also are also a good vegetarian source of Omega 3. Blueberries top the list with 174mg of Omega 3 per 1 cup serving.
Lastly it is important to understand the motivation behind your daughter’s reasons for going vegetarian, is she using this diet change for unnecessary weight loss? Or does she have genuine concern for animal welfare and the planet. If it is to lose weight then please ensure you consult a nutritionist or naturopath as it could be an indicator for an eating disorder.
I hope this was helpful
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Murray, M. T., & Pizzorno, J. E. (2012). The encyclopedia of heaing foods NY: Atria Paperback.
Stoker, H. S. (2013). General, Organic, and Biological Chemistry (Vol. 6). Belmont, CA 94002-3098: Brooks Cole, Cengage Learning.
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