Vitamin B9 (Folic Acid)

Ans. is ‘a’ i.e., Fortified in all wheat products in India like as in USA

o India has not yet adopted recommendation of fortification of all wheat products in India with folic acid.

o All other options are correct.

Ans. is ‘None’ 

o Folic acid requirement during lactation is 300 mg/d.

Ans. B: 150 microgram/day

The dietary intake values of folate as recommended by ICMR are:

• Healthy adults: 100mcg per day
• In pregnancy: 400mcg per day
• During lactation: 150mcg per day
• Children: 100 mcg per day

Ans. A: First

Ans. is ‘a’ i.e., 80-120 μg

• Recommended daily allowances of folic acid are:-

1. Healthy adults → 200 micro gm.(mcg)
2. Pregnancy → 500 mcg
3. Lactation  → 300 mcg
4. Children → 80-120 mcg

Ans. is ‘a’ i.e., Methylene THF

Folic acid

• The active form of folic acid (pteroyl glutamate) is tetrahydrofolate (THF).
• THF serves as a carrier of one-carbon (C₁) unit⁰ during several biosynthetic reactions like nucleic acid^Q and amino acid metabolism.
• Two other cofactors are also known to be involved in the addition of one carbon (C₁) unit to a metabolic precursor, biotin in carboxylation reaction and S-adenosylmethionine (SAM) as methylating agent.
• However, folic acid is more versatile than either of these two because it can transfer the C, units in several oxidation states.
• THF acts as a carrier of one carbon unit0.
• The one carbon units can be : Methyl (C.11₃), methylene (CH₂), methenyl (CH), formyl (CHO), orformimino (CH =NH).
• One carbon unit binds to THF through N⁵ or N¹° or both N⁵, N’° position.
• For example, if formyl unit is attached to N-5, it is cal led N⁵-formyl THF; if methylene unit is attached to both N⁵ and 1\l’°, it is called N⁵, N’° methylene THF.
• Carbon units attached to N5 are formyl, formimino, or methyl; attached to N’° is formyl; and attached to both N⁵-N¹⁰ are methylene or methenyl.
• So, various possible THF are : – N⁵-Formyl THF, N⁵-formimino THF, N⁵-methyl THF, N¹°-formyl THF, N⁵-N¹⁰­methylene THF and N⁵-N’°-methenyl THF.
• THF receives the C, units from various donor molecules during catabolic reactions and can transfers them to specific acceptors for the synthesis of various compounds.
• The major point of entry for one-carbon unit into substituted folates is methylene THF, which is formed by the reaction of glycine, serine and choline. Serine is the most important source of substituted folates for biosynthetic reactions, and activity of serine hydroxymethyltransferase is regulated by the state of folate substitution and availability of folate.

Ans. is ‘c’ i.e., Methyl THE

• Folic acid is absorbed in the jejunum.
• Following absorption, folic acid is transported in blood by two (3-globulins.
• The major circulating form is methyltetrahydrofolate and the normal concentration range is 5-15 ng/ml. 
• Once it arrives in the liver, the methyl derivates are taken up by hepatocytes where various coenzyme are produced. o Folic acid is not stored in the body.

Remembers

• Major circulating form of folic acid —0 methyl THE
• Major point of entery for 1 carbon transfer by substitued folate -4 methylene THE

Ans. is ‘c’ i.e., Pregnant females 

• Body stores of folate are not large, about 5-10 mg, and therefore, folate deficiency can develop quickly.
• Folic acid requirements are greatest in conditions where there is rapid cell multiplication, such as during growth in young children and during pregnancy.
• Folic acid supplementation during pregnancy has been found to increase the birth weight of infants and decrease the incidence of low birth babies.
• Intake values recommended by ICMR (2010) are given below 

                               Per day

Healthy adults          200 mcg

Pregnancy                500 mcg

Lactation                  300 mcg

Children                   80-120 mcg