My first recommendation is to use products that contain vitamin B6 to help prevent varicose vains from forming. This can be done by taking supplements that have vitamin B6. You can find a great review of vitamin B6 supplements at this link. If you want to be sure of your vitamin B6, be sure to read my article about the different types of vitamin B6. The other type of vitamin that I recommend is the vitamin B6 from the B vitamin family. I will discuss vitamin B12 in detail later.
Another good source of vitamin B12 is from animal sources like liver and heart. The best time to get this type of vitamin is during the first 2 months of your pregnancy. The vitamin B12 will then continue to build up until the day of delivery. The best way to get B12 from the liver is to eat liver every day in the first trimester. You can buy liver from a vet. There are many brands available. Make sure the product you are buying is the best. There are a lot of supplements available now. It's not just about B12. Many people who are allergic to some of the supplements on the market are allergic to the liver products as well. Check the labels before you purchase.