Vitamin C has very important functions in the human body. It is necessary for the formation of the collagen – a substance that is included in the structure of the bones, teeth and blood vessels. Vitamin C can aid in strengthening bones, helps the blood vessels to be more elastic and can help your wounds heal fast.
Food Sources
Good sources of Vitamin C are:
* Avocado
* Black currants
* Blueberries
* Broccoli
* Brussels sprouts
* Cabbage
* Collard greens
* Grapefruit
* Green pepper
* Guava
* Kale, lemon
* Lime
* Mango
* Melon
* Orange
* Papaya
* Pineapple
* Potato
* Rose hip
* Spinach
* Strawberry
* Tomato
* Watercress
Vitamin C Requirement
The current recommended dietary intake for vitamin C is 90 mg for men and 75 mg for women (add an extra 35 mg for smokers). There's no good evidence that megadoses of vitamin C improve health.
As the evidence continues to unfold, 200 to 300 mg of vitamin C a day appears to be a good target. This is easy to hit with a good diet and a standard multivitamin. Excellent food sources of vitamin C are citrus fruits or citrus juices, berries, green and red peppers, tomatoes, broccoli, and spinach. Many breakfast cereals are also fortified with vitamin C.
Vitamin C Deficiency
Vitamin C deficiency causes scurvy. In adults, the deficiency usually results from a diet low in vitamin C. For example, vitamin C deficiency may develop in people who eat only such foods as dried meat, tea, toast, and canned vegetables.
Pregnancy, breastfeeding, surgery, and burns can significantly increase the body's requirements for vitamin C and the risk of vitamin C deficiency. Smoking increases the vitamin C requirement by 30 to 50%.
Scurvy in infants is rare because breast milk usually supplies enough vitamin C and infant formulas are fortified with the vitamin.
In adults, a few months of a diet low in vitamin C can cause bleeding under the skin (particularly around hair follicles or as bruises), around the gums, and into the joints. Symptoms may include irritability, depression, weight loss, fatigue, and general weakness. The gums become swollen, purple, and spongy. The teeth eventually loosen. Infections may develop, and wounds do not heal.
In infants, symptoms include irritability, pain during movement, and loss of appetite. Infants do not gain weight as they normally do. Bone growth is impaired, and bleeding and anemia may occur.
The diagnosis of scurvy is based on symptoms. Blood tests detect a very low level of vitamin C. Scurvy is treated with daily vitamin C supplements. Such treatment plus iron supplements can cure the anemia.
Tuesday, February 1, 2011
Ants' ecosystem role is 'key'
Research by the University of Exeter has revealed that ants have a big impact on their local environment as a result of their activity as 'ecosystem engineers' and predators.
Ecohydrology - New Academic Journal Library Recommendation - onlinelibrary.wiley.com/journal/eco
The study, published in the Journal of Animal Ecology, found that ants have two distinct effects on their local environment.
Firstly, through moving of soil by nest building activity and by collecting food they affect the level of nutrients in the soil. This can indirectly impact the local populations of many animal groups, from decomposers such as Collembola, to species much higher up the food chain.
Secondly, they prey on a wide range of other animals, including larger prey which can be attacked by vast numbers of ant workers.
Dirk Sanders, an author of the study from the university's Centre for Ecology and Conservation, said: "Ants are very effective predators which thrive in huge numbers. They're also very territorial and very aggressive, defending their resources and territory against other predators. All of this means they have a strong influence on their surrounding area.
"In this research, we studied for the first time how big this impact is and the subtleties of it. What we found is that despite being predators, their presence can also lead to an increase in density and diversity of other animal groups. They genuinely play a key role in the local environment, having a big influence on the grassland food web."
The study, carried out in Germany, studied the impact of the presence of different combinations and densities of black garden ants (Lasius niger) and common red ants (Myrmica rubra), both species which can be found across Europe, including in the UK.
It found that a low density of ants in an area increased the diversity and density of other animals in the local area, particularly the density of herbivores and decomposers. At higher densities ants had no or the opposite effect, showing that predation is counteracting the positive influence.
Dr Frank van Veen, another author on the study, said: "What we find is that the impact of ants on soil nutrient levels has a positive effect on animal groups at low levels, but as the number of ants increases, their predatory impacts have the bigger effect – thereby counteracting the positive influence via ecosystem engineering."
More information: The full paper from the study, Ecosystem engineering and predation: the multi-trophic impact of two ant species, can be viewed online at: http://onlinelibra … 01796.x/full
Ecohydrology - New Academic Journal Library Recommendation - onlinelibrary.wiley.com/journal/eco
The study, published in the Journal of Animal Ecology, found that ants have two distinct effects on their local environment.
Firstly, through moving of soil by nest building activity and by collecting food they affect the level of nutrients in the soil. This can indirectly impact the local populations of many animal groups, from decomposers such as Collembola, to species much higher up the food chain.
Secondly, they prey on a wide range of other animals, including larger prey which can be attacked by vast numbers of ant workers.
Dirk Sanders, an author of the study from the university's Centre for Ecology and Conservation, said: "Ants are very effective predators which thrive in huge numbers. They're also very territorial and very aggressive, defending their resources and territory against other predators. All of this means they have a strong influence on their surrounding area.
"In this research, we studied for the first time how big this impact is and the subtleties of it. What we found is that despite being predators, their presence can also lead to an increase in density and diversity of other animal groups. They genuinely play a key role in the local environment, having a big influence on the grassland food web."
The study, carried out in Germany, studied the impact of the presence of different combinations and densities of black garden ants (Lasius niger) and common red ants (Myrmica rubra), both species which can be found across Europe, including in the UK.
It found that a low density of ants in an area increased the diversity and density of other animals in the local area, particularly the density of herbivores and decomposers. At higher densities ants had no or the opposite effect, showing that predation is counteracting the positive influence.
Dr Frank van Veen, another author on the study, said: "What we find is that the impact of ants on soil nutrient levels has a positive effect on animal groups at low levels, but as the number of ants increases, their predatory impacts have the bigger effect – thereby counteracting the positive influence via ecosystem engineering."
More information: The full paper from the study, Ecosystem engineering and predation: the multi-trophic impact of two ant species, can be viewed online at: http://onlinelibra … 01796.x/full
RLSS I - Rashtriya Life Saving Society India
The Rashtriya Life Saving Society (India) RLSS (I) is a national, non-profit, voluntary organization dedicated to helping people to learn modern lifesaving techniques. We are a leading provider of training in first aid, resuscitation, water safety, life saving and life guarding skills in India. The Society is a member of the International Life Saving Federation and branch of the Royal Life Saving Society (Commonwealth).
There are many ways you can become involved with the RLSS (I). This can range from learning new skills and qualifying as a first aider or lifesaver, getting a recognized qualification to be a trainer or making a donation to help us provide lifesaving information and training for young and old alike.
The desire to help is of little value unless it is accompanied by informed and keen action or first aid.It is headquartered at Pune. And it is situated all over India.
Further details:http://www.lifesavingindia.org
There are many ways you can become involved with the RLSS (I). This can range from learning new skills and qualifying as a first aider or lifesaver, getting a recognized qualification to be a trainer or making a donation to help us provide lifesaving information and training for young and old alike.
The desire to help is of little value unless it is accompanied by informed and keen action or first aid.It is headquartered at Pune. And it is situated all over India.
Further details:http://www.lifesavingindia.org
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