Bone markers during a 6-month space flight: effects of vitamin K supplementation.

Article Details

Citation

Copy to clipboard

Vermeer C, Wolf J, Craciun AM, Knapen MH

Bone markers during a 6-month space flight: effects of vitamin K supplementation.

J Gravit Physiol. 1998 Oct;5(2):65-9.

PubMed ID

11541904 [ View in PubMed

]

Abstract

Rapid bone loss is a serious health problem for astronauts during long lasting missions in space. We have recorded the changes of biochemical markers for bone metabolism in one of the astronauts during the 6-month space flight of the EUROMIR-95 mission. Immediately after launch both bone resorption markers and urinary calcium excretion increased about two fold, whereas bone formation markers remained unchanged. After 12 1/2 weeks the astronaut received vitamin K1 (10 mg/day for 6 weeks). Vitamin K is known to be involved in the formation of gamma-carboxyglutamate (Gla) in proteins, such as the calcium-binding bone Gla-proteins osteocalcin and matrix Gla-protein. Concomitant with the start of vitamin K treatment, the calcium-binding capacity of osteocalcin increased, and so did the urinary excretion of free Gla. This is suggestive for a subclinical vitamin K-deficiency in the astronaut before vitamin K-supplementation. During periods of high vitamin K status markers for bone formation (osteocalcin and bone alkaline phosphatase) had increased as compared to the first part of the flight. The mean increases were 14 and 23%, respectively. Our data suggest that increased intake of vitamin K may contribute to counteracting microgravity-induced loss of bone mass during long lasting space missions, but need confirmation in more astronauts.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Phylloquinone	Osteocalcin	Protein	Humans	Unknown	Agonist	Details