Question

Science of Nutrition

5) List one example of a Mineral and another example of a vitamin that are important for our immune system

6) What are the teratogens? Please list two examples of food items that should be avoided during pregnancy.

7) What is Bio availability ? Please list two examples of increased bio availability and another two examples of decreased bio availability.

***please be specific/detailed

Answer 1

5.Zinc is a important mineral for our immune system.Zinc helps in functioning of immune cells like macrophages and neutrophils Human body need zinc to activate T lymphocytes  .Zinc helps the immune system to fight against the bacteria and viruses.Zinc helps to heal wounds and keeps the immune system strong.Lack of zinc can make a person susceptible to disease.The recommended dietary zinc needed of men is 11 mg per day and women is 8 mg per day.During pregnancy women need more zinc.

Vitamin C is important vitamin to protect against infection.Vitamin C helps to strengthen the immune system.Vitamin c increases the function of phagocytes(Phagocytes are type of white blood cell that surrounds pathogens,and destroy them.)Vitamin C helps in the production of interferons.Interferons are produced when pathogen is there.Vitamin C enhance cytokine production.Vitamin C enhances the production of T -lymphocytes.

6.Teratogens are any substances which are capable of interfering with development of fetus and causes birth defects.Teratogen can affect embryo in different ways like physical malformation,emotional development of the child,and cause complication in pregnancy like abortions or pre- term labors.Common teratogenic agents are infectious agents like herpes simplex,syphilis,certain drugs,chemicals.Foods to be avoided in pregnancy are:

1.Unpasteurized diary products:In pasteurization most of the bacterias are killed.Unpasteurized products is dangerous for pregnant woman and increases the risk for the foetus.Raw milk,unpasteurized cheese can contain harmful bacteria and can have dangerous effect on the foetus.

2.High mercury fish:Fishes like shark,tuna,swordfish,mackerel have high amount of mercury in their system.Mercury is a toxic element and consumption of this fishes are harmful for the foetus.

7.Bioavailability is the ability of a drug to be absorbed and used by the body.Bioavailability is the fraction of the administered drug that reaches the circulation.In IV administration bioavailability is 100% while in oral route it is less.Certain factors can influence the bioavailability like drug taken with food or drug formulation and interaction with food.

Increased bioavailability can be seen IV drugs.Here the drug reaches the systemic circulation immediately and there is no first pass metabolism.Certain food can increase the bioavailability of drug.Griseofulvin absorption is increased in the presence of fatty food.Food high in protein increases the bioavailability of propranolol.

Decreased bioavailability is seen in drugs adminstered by mouth.First pass metabolism occurs and this means drugs administered by mouth is absorbed from GIT and transported by the portal vein to the liver.Only a small amount of drugs reaches the systemic circulation.

Chemical reactions that reduce absorption can decrease bioavailability.Drugs can form a complex like tetracycline and polyvalent metal ions.

Insufficient time for absorption in GIT can lower bioavailability.If the drug does not dissolve readily it can lower bioavailability.

Delayed gastric emptying in drugs like penicillin reduce the bioavailability.