Nutrition

Nutrient Nugget – Vitamin C

Why do we need vitamin C?

Vitamin C, also called ascorbic acid, has a huuuuuge list of functions. It’s an anti-oxidant, which means it helps to keep your cells healthy and reduce risk of cardiovascular disease, diabetes and inflammatory diseases. Vitamin C is also required to make collagen; a type of protein found in connective tissue (skin and blood vessels), which makes vitamin C is essential for muscle maintenance. It activates many hormones and enzymes, including those linked with bile production and liver metabolism. Plus, vitamin C plays an important role within our nervous system, aids wound healing and helps our body absorb iron. See, I said it was a long list!

citrusWhere do we get it from?

Our bodies are unable to make vitamin C, so all of what we need has to come from our diet. Vitamin C is found in lots of fruit and vegetables; oranges and other citrus fruits, kiwi, mango, blackcurrants, tomatoes, peppers, broccoli, potatoes, sweet potato and brussels sprouts.

 

How much do we need?

Adults are recommended 40 milligram (mg) per day* (Department of Health, 1991). Pregnant women should intake an extra 10mg for the last trimester, and breastfeeding women are advised to aim for a total of 70mg per day. Recommended intakes for other ages are outlined below:
0-1 year: 25mg
1-10 years: 30mg
11-14 years: 35mg

*People who smoke regularly use up more vitamin C and so may require up to 80mg per day.

To put this into perspective, a small orange contains 50mg of vitamin C, a medium sweet potato has about 20mg and a cup of broccoli will provide you around 80mg. As you can see, if you eat fruit and vegetables, you should have no problem reaching your recommended intake!

What if we don’t get enough?

You may have heard stories of when sailors and pirates used to suffer from a disease called scurvy. This is the name given to the disease caused when we don’t have enough vitamin C. Luckily, it’s not very common anymore apart from those who do not consume enough fruits and vegetables. Symptoms include; feeling fatigued, muscle weakness, irritability, pain in joints, bleeding gums and red/blue spots appearing on your skin. The disease is treated by the person taking vitamin C supplements and eating foods high in vitamin C.

What if we get too much?

Having over 1000mg (20 oranges!) can cause abdominal discomfort, stomach pain, flatulence and diarrhoea. Some people take high doses of vitamin C because they believe that it can help prevent the common cold. There is little evidence to support complete prevention, but high doses may help reduce the severity of some symptoms. In addition, it is likely that anything over 500mg of vitamin C at any one time won’t be absorbed.

Where can I find out more?

NHS Choices – Vitamin C
NHS Choices – Scurvy
Vitamin C and the common cold

Department of Health (1991). Dietary reference values for food energy and nutrients for the United Kingdom.

Nutrition

Nutrient Nugget – Iron

Why do we need iron?

Iron plays an important role in several essential bodily functions. It’s a crucial ingredient for haemoglobin, the substance found in red blood cells that carries oxygen around the body. Without oxygen, our organs and cells would not be able to respire; a process that keeps us alive! Although transport of oxygen is a principle function of iron, it is also a component of enzymes and helps with energy production.

IronWhere do we get it from?

There are two types of iron; haem and non-haem. Haem sources of iron are found in meat and fish, and are more easily absorbed by the body than non-haem sources. For this reason, vegans and vegetarians should take extra care to include plenty of iron rich foods in their diet. See my post on ‘how to be a healthy veggie‘ for more information.

Foods containing high levels of iron include; meat (especially offal), fish, eggs, dark green vegetables (spinach, swiss chard, kale, bok choy), lentils, beans (kidney, black, chic peas), wholegrains, nuts and dried fruit.

Some foods, such as soy bean products (milk, yoghurts and tofu), breakfast cereals and flour are fortified with iron. These can be a handy source, especially for fussy eaters, so check the labels of your favourites!

A handy hint: Vitamin C can help our body absorb more iron. So by having a source of vitamin C alongside your meal, you’ll get the most iron you can from it. Good sources of vitamin C include; citrus fruits, peppers, broccoli and sweet potato.

You should also avoid having tea and coffee at the same time as meals, as they contain phytates which bind with the iron and make it more difficult for the body to absorb.

How much do we need?

Iron reference nutrient intake gradually increases throughout childhood. The recommended daily intake for the adult population is 8.7mg for men and 14.8mg for women. Women have a higher requirement to allow for losses during menstruation (Department of Health, 1991).

Below shows the amount of iron contained in 50g of;

Liver* = 5mg

Lentils = 1.5mg

Dried apricots = 2mg

Broccoli = 0.5mg

Breakfast cereals (30g portion) = 4mg (depends on cereal)

An average steak will provide about 7mg of iron

*Liver is not recommended during pregnancy due to its high vitamin A content.

What if we don’t get enough?

Iron deficiency anemia or IDA is one of the most common nutritional deficiencies in the world. It occurs when a lack of iron in the body results in a low number of red blood cells. IDA can result in the following symptoms; fatigue, breathlessness, insomnia, loss of appetite, decreased immunity, heart palpitations and a tingling sensation in your fingers and toes (paraesthesia).

IDA is usually easily treated by taking a iron supplement which boosts the levels of iron in your body. Recurrence can then be prevented by ensuring a diet rich in good sources of iron. Some women who regularly have heavy periods may need to take an iron supplement, ask your doctor for more advice.

What if we get too much?

Too much iron usually occurs through use of a supplement but can lead to constipation, nausea, vomiting, and stomach pain. Intakes of less than 20mg are unlikely to cause any problems, but very high doses can be fatal, so be sure to keep iron supplements out of reach of children.

Where can I find out more?

NHS Choices – Iron deficiency anaemia

NHS Choices – Iron

Department of Health (1991). Dietary reference values for food energy and nutrients for the United Kingdom.

Dietary Conditions, Healthy Living

How to be a healthy veggie

I’m not vegetarian, but I do enjoy vegetarian food. Every Monday, I experiment with a recipe that typically contains meat and try to make it with lentils, beans or another legume. I support ‘Meat Free Mondays’ for a couple of reasons; I like the taste of legumes and pulses, they’re lower in saturated fats than red meat PLUS I like the challenge of trying to make something where my boyfriend doesn’t notice the meat is ‘missing’!

If you’re thinking about becoming vegetarian or vegan though, it’s more complicated than just cutting meat and animal products from your diet.

First things first, a lot will depend to what degree you cut out meat. Is it just red meat (demi-vegetarian)? No red meat or poultry but you’ll eat fish (pescatarian)? No animals but still eat eggs and dairy (lacto-ovo-vegetarian)? Or no animals or animal products at all (vegan)?
All of these animal products contain nutrients that your body needs, so naturally, if you’re cutting them out then you need to find an alternative source.

Proteins are made up of tiny pieces called amino acids. Amino acids are required by the body to make hormones, enzymes and replace muscle tissue. Some amino acids are essential; the body cannot make them, so they need to be ingested through our diet. Most meats and animal products are called complete proteins, which means that they provide all of the 9 essential amino acids. If still consuming dairy products and eggs, these are valuable sources of protein too – with eggs being a complete protein.

Quinoa and soya beans are also technically complete proteins, although they do not contain as higher levels of these amino acids as animal products do. Therefore, it’s best to mix things up a bit! Quinoa, despite it being a complete protein, is not a rich source, so it should not be the only protein containing food vegetarians eat. Your diet should also contain rich sources, ie; eggs, chic peas, beans and lentils. However, most vegan sources of protein are not complete, meaning that in order to obtain all of the essential amino acids, a couple of protein sources need to be mixed. Legumes (lentils, chic peas, beans etc) are typically low in the essential amino acid called methionine. Grains (rice, cous-cous, brown bread etc), while containing methionine, are insufficient in lysine. By combining legume + grain, vegetarians or vegans can obtain a complete protein. For example; beans on toast, rice and black bean curry, lentil soup and bread or pita bread and hummus. Meat eaters and vegetarians should aim to have 2-3 servings of complete proteins per day.

Iron

Another nutrient to be aware of is iron. Women have a higher requirement of iron than men (due to menstruation) and intakes are typically below what is recommended, especially in adolescent girls. Iron found in meat is called haem-iron, and is more readily absorbed than non-haem iron. For this reason, female vegetarians especially, need to ensure that they’re having a couple of sources of non-haem iron daily. Iron can be found in beans and pulses, eggs, fortified breakfast cereals, dark green leafy vegetables (like spinach, broccoli and swiss chard), wholemeal flour, dried apricots and seeds. As I said, these non-haem sources of iron aren’t so easily absorbed by the body, however, there are a few tips than can help enhance absorption. Vitamin C (found in citrus fruits, peppers and sweet potato) helps improve the amount of iron we can obtain from food. So having a glass of orange juice with cereal or some sweet potato in your lentil soup will help up your iron intake. Also, avoid having tea and coffee alongside a meal as they contain tannins and phytates that bind with iron and make it more difficult for the body to absorb.

If vegan, good sources of calcium will be required to replace calcium obtained from dairy (see my nutrient nugget for more info on calcium). Calcium is found in green leafy veg like; kale, broccoli, rocket and watercress, beans, pulses, fish where you eat the bones (tinned mackerel/sardines), almonds, brazil nuts, sesame seeds and dried apricots. Some soya milks and tofu are also fortified with calcium. Vitamin D (obtained from sunlight) enhances calcium absorption, so those at risk of poor vitamin D status should eat a variety of the above foods daily and you should consider a vitamin D supplement. See my vitamin D post.

Vitamin B12 is found in animals and animal products. The requirement for this nutrient is small so deficiency is rare but strict vegans should consume a fortified food. For example; yeast extract (marmite), fortified soya products, breakfast cereals and vegetable stocks.

Finally, as milk is an important source of iodine, vegans are at risk of low intakes. If this is the case it’s recommended to use iodized salt or take a nutritional supplement.

In order to get all the vitamins and minerals we need, a large variety of fruits and vegetables should be eaten. Think about eating as many different colours as possible! This, alongside beans, lentils, grains and nuts will help ensure your vegetarian or vegan diet is adequate in all nutrients.

Nutrition

Nutrient Nugget – Calcium

Why do we need calcium?
Calcium is the most abundant mineral in the body. Most people know that calcium is important for bone and teeth health, but it also helps with nerve signalling, blood clotting and regulating muscle contractions (including the heart).

Where do we get it from?
Good sources of calcium include dairy products, soy beans, green leafy vegetables (broccoli, kale and cabbage) and nuts. Any fish where you eat the bones (eg. sardines or white bait) will also contribute calcium to the diet.
Fortified flour is often used to make bread and other products, so although this is not a rich source, some of our calcium comes from these products as they are consumed so regularly. Some brands of tofu and breakfast cereal are fortified with calcium too (check the label).

How much do we need?
Calcium requirements change for different ages. This is because of needs associated with bone growth. Below shows calcium reference nutrient intakes for different ages (Department of Health, 1991).
0-12 months: 525mg
1-3 years: 350mg
4-6 years: 450mg
7-10 years: 550mg
11-18 years: 1000mg (male) and 800mg (female)
19+ years: 700mg

A 200ml glass of cows milk will provide you with 250mg of calcium and a pot of yoghurt contains about 150mg. Vegan sources are not as rich, with 100g of broccoli providing around 40mg of calcium.

What if we don’t get enough?
Not having enough calcium over a long period of time could lead to osteoporosis and increased risk of bone fractures in later life. It can also cause development of rickets in children. See my post on vitamin D for more information on rickets.

What if we get too much?
Too much calcium usually occurs through use of a supplement but can lead to stomach pain and bowel disturbances. Intakes of less than 1500mg are unlikely to cause any problems.

Where can I find out more?
NHS Choices
The Vegetarian Resource Group

 

Department of Health (1991). Dietary reference values for food energy and nutrients for the United Kingdom.

Nutrition

Nutrient Nugget – Vitamin D

This week I’m going to start a new series of posts called ‘nutrient nuggets’. I thought it would be helpful to give you snippets of information about a particular nutrient, mineral or vitamin.

So, as it’s summer…where better to kick off than with vitamin D?

Why do we need vitamin D?
Vitamin D helps regulate the amount of calcium and phosphate in the body, these are all are used in combination to help make our bones strong and healthy. Vitamin D has many other important roles in the body, including helping maintain muscular strength, immune function and reducing inflammation. Vitamin D also plays an essential role in cell growth; where cells become specialised for a specific function.

oily fishWhere do we get it from?
The majority (80-90%) of vitamin D is obtained from the sun; when sunlight hits the skin, it causes a reaction under our skin which produces vitamin D.
There are only a couple of dietary sources of vitamin D. Good sources are; oily fish (herring, mackerel, salmon, sardines etc), eggs and fortified fat spreads (required by UK law to contain vitamin D). Some yoghurts and breakfast cereals are also fortified with vitamin D.

How much do we need?
Exposing your face and forearms to the sun a few times a week should be sufficient to maintain good vitamin D levels through the summer. (Remember to cover up and use suncream when out for extended periods and at the hottest times of the day to reduce the risk of skin damage and skin cancer). However, through the winter, it is not possible for our bodies to use sunlight to make vitamin D and this can lead to low levels. It is recommended that everyone in the UK consider taking a 10 microgram (μg) vitamin D supplement from October to March.

Certain population groups such as pregnant women, babies, people who cover their skin when outdoors and those with darker skin are at increased risk of vitamin D deficiency. For these groups, a daily 10 microgram (μg) vitamin D supplement is recommended throughout the year.

The Department of Health in the UK recommends that pregnant and breastfeeding mums should also take a 10μg supplement of vitamin D to ensure she is meeting her nutritional requirements and to help build adequate nutrient stores. Breastfed babies and children aged 1 to 4 years should also take a daily vitamin D supplement (up to 10 micrograms (μg)). Formula fed babies should not take vitamin D unless they are having less than 500ml formula a day as formula is fortified with vitamin D.

What if we don’t get enough?
Early signs of deficiency can be fatigue, muscle aches/weakness and bone pain. A lack of vitamin D over the longer term can cause a bone deformity disorder in children called rickets. Rickets causes the bones to become soft, tender and weak. It can also cause problems with developing teeth. In adults, a similar bone softening condition called osteomalacia can occur.

If you are concerned about your vitamin D levels, you should speak to your doctor, or ask to be referred to a dietitian.

What if we get too much?
Too much vitamin D can upset the balance of calcium and phosphate, provoking the removal of calcium from bones, weakening them. This imbalance can also lead to excess calcium being absorbed rather than being excreted. Excess calcium can be deposited in the kidneys and cause damage.

Given the low amount of vitamin D in most diets, it is most likely vitamin D in excess would occur as a result of taking too higher dose of supplement. The NHS state adults should not take any more than 100 micrograms (μg) of vitamin D per day, children age 1 to 10 years no more than 50 micrograms (μg) and babies less than 1 year no more than 25 micrograms (μg) daily.

What can we do to prevent deficiency diseases?
Rickets and osteomalacia can be prevented by eating a healthy, balanced diet incorporating some sources of vitamin D and taking supplements as recommended above. The NHS also advises 20-30 minutes of sun on the face and forearms a couple of times a week. Please note: You should still use suncream to protect your skin.

Where can I find out more?
Patient.co.uk
NHS: Vitamin D
Find out more about rickets on the NHS Choices website, here.
The Journal of Family Healthcare have a great article detailing causes, prevalence and prevention of rickets.

 

[Updated May 2020]