Blood replacement

I brought my dad to have follow up checking and at the same time i plan to replace blood for my dad's usage during his operation. So me and JJ went to the lab and fill up the form. After that we have to go through a simple checking. I tot i am sure to qualify as i donate blood before many years ago :)....but to my surprise, the lab assistant say that i am not qualify before my hemoglobin is just enough for myself and no extra for donation :(.. my scale is only 11 and to be qualified, need to be in the range of 13-17...too bad.
Next is JJ's turn, haha..the result also show that he is not qualified but the lab assistant was not convince by the result as he say normally guys should have enough blood to donate (especially for him, so big size...hehe..this is what i think lar, not mention by lab assistant :))
SO the lab assistant take another blood sample from his arm (the first time is from the finger) and luckily this time, he is slidely more than 13 - Qualify!
According to the lab assistant, we need 3 things to built hemoglobin - Iron, B12 and Folic. Iron is the most important part and it can be found in meat and cockles.
Another thing we have learnt from the lab assistant is that for those whose family have high blood pressure history, better donate blood often as it can helps regulate blood circulation and hence reduce the risk to get high blood pressure.
It is a good learning for me and JJ :)