The best swimmers among female Ironman triathletes complete the swimming portion of the event in 50 minutes to an hour. At the World Championship, the cutoff time for all competitors is two hours, 20 minutes. Any participant who fails to complete the 2.2-mile swim within that time is eliminated from the competition.
There are two sources of this essential vitamin, including vitamin K1, or phylloquinone which is primarily found in green leafy vegetables and vitamin K2 or menaquinone which is synthesized by certain intestinal bacteria.
Methyl-B 12 is absorbed by an intestinal mechanism using intrinsic factor and by a diffusion process in which approximately 1% of the oral dose is absorbed. The human physiology of vitamin B 12 is complex, and therefore is prone to mishaps leading to vitamin B12 deficiency.ecause intrinsic factor is crucial for the normal absorption of B 12, its lack in pernicious anemia causes a vitamin B12 deficiency. Many other subtler kinds of vitamin B 12 deficiency and their biochemical effects have since been elucidated.