I think poor circulation is genetic - the cold hands gene! - but there are some things you could do to prevent it becoming a serious problem (alongside the above), by considering your cholesterol levels (perhaps you can get them tested? the highest cholesterol score I heard of amongst my friends, belonged to a whip-thin, veganish, yoga teacher

).
Eat oats everyday
Cut out all trans-fats
and ..... get your
7 a day (5 for children, 7 for women, 9 for men - the 5 a day thing is just so that people who barely eat any fruit or veg aspire to something rather than nothing).
baby-loving, earth-digging, bread-baking, jam-making, off-grid, off-road 21st century domestic goddess....
...and
eco campsite owner