Vitamin D metabolism

UV rays from sun act on skin, convert Cholecalciferol (CC) --> 25 Hydroxy CC in liver --> 1,25 Di Hydroxy CC in kidney.
So there are two hydroxylation reactions, first in Liver, second in Kidney. Remember this: You have 1 liver, 2 kidneys; So hydroxylation 1st reaction in your 1 liver and 2nd hydroxylation in 2 kidneys.

Vitamins and Hypervitaminosis

Fat soluble vitamins are A, D, E, K (Remember FADEK)

Hypervitaminosis A causes Anomalies (teratogenicity)

Hypervitaminosis E causes necrotising Enterocolitis

Hypervitaminosis K causes Kernicterus due to hemolysis

Iron content in body and in milk

Total quantity of " I R O N " in human body is 4 gms (=  number of letters inthe word " I R O N ")

Iron content in Milk = 0.4 mg