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liveonearth

Nutrition: Vitamin K and Phosphorus


VITAMIN K AND PHOSPHORUS

VITAMIN K
blood clotting
bone metabolism
K1 = phylloquinone, made by plants, what we get in our diet
K2 = menaquinones, several forms, MK-n where n = number of side chains
K2 produced by bacteria of by converting K1 in animals
Japanese fermented foods contain natto and miso: high in K2
MK-4 is osteoporosis tx in Asia, this is a side chain 4 units long
natto has MK-7
MK-4 best of osteoporosis, boosts bone mass, this is available on the market
body is good at recycling vitamin K
acute deficiency is rare

ONE REACTION VITAMIN
gamma carboxylation is the only thing that vitamin K does
that enzyme essential for making several clotting factors incl prothrombin
exploited by anticoag drugs incl warfarin which impair recycling of vit K
bone mineralization: synthesis of three bone proteins incl: osteocalcin
bone protein also found in blood vessels: matrix-Gla protein prevents calcification of BV's

DEFICIENCY
impaired blood clotting, easy bruising, nosebleed, bleeding gums
unusual: K is widespread, K is recycled well; gut bact make K
adults on anticoagulants at risk
newborns at risk

REQUIREMENTS
adult adequate intake: 120 mcg/day men, 90 mcg/day women
75% may miss these targets
these numbers not based on long term bone health
some studies suggest increased protection at 250 mcg/day or more
LPI: use multi and leafy greens
NO KNOWN UPPER LIMIT, no toxicity
use w/ care if using anticoagulants

SOURCES OF VITAMIN K
high chlorophyll plants
green leafies
non-hydrogenated vegetable oil
p 5 of notes
kale
intestinal bacteria (minor source)
supplements (not always in multis)
lots in bone support multis
K2 has become available, very expensive
Thorne brand liquid product is his fave but not cheap

STUDYING BONE LOSS
under-carboxylated osteocalcin in blood and low dietary vit K correlate with fracture risk
1000 mcg/day reduces under-carbox osteocalcin, improved bone density in some studies
no studies yet on fracture prevention
Pharmaceutical doses of K2 (MK-4) is 45,000 mcg/day (45 mg)
Japanese research finds dramatic reduction in fx risk with this huge dose


PHOSPHORUS
not a nutrient of concern because it is readily available
unless maybe too much relative to Ca++
present in food and bio tissues as phosphate (PO4 -3)
in phospholipids, high energy phosphates (ATP), nucleic acids
functional roles: acid-base buffer, cofactor for phosphorylation rxns
easily absorbed in intestine, easily exreted by kidneys
affected by PTH and vit D but not as tightly regulated as calcium
concern exists that too much might cause bone loss
esp in women and children who consume too little calcium
RDA = 700 mg/day
adult average intake over 1000 mg/day
food additives: cola (phosphoric acid), preservatives (in bread)
abundant in protein foods
some plant sources may be poorly absorbed
usually omitted from supplements unless with calcium (calcium phosphate)
some say avoid phosphate containing supps
hyperphosphatemia found only with kidney or parathyroid dysfunction
UL = 4000 mg/day under 70 years of age, 3000 over 70
some older women have low phosphate intake, they're the only ones approaching deficiency
Tags: aging, blood, bones, nutrition, vit k, vitamins
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