i took folic acid until around 12 weeks - was not convinced my dates were right, but a few day either side won't harm.
then took pregnacare - and they have small amount of folic acid in too.
if you are worried, you could always just up your intake of folic acid rich foods. Took this from the babcy centre website for you:
Leafy green vegetables are a good source, so try to have a large bowl of salad daily. Other sources include:
• 11 Brussels sprouts: 127 mcg
• large jacket potato: 39 mcg
• 4 tbsp black eyed beans: 220 mcg
• 7 tbsp bran flakes: 113 mcg
• 25g / 1oz wheat germ: 100 mcg
• 4 spears steamed or boiled asparagus: 88 mcg
• medium sized papaya: 115 mcg.
• 2 spears steamed broccoli: 61 mcg
• large orange: 54 mcg
• large hard-boiled egg: 22 mcg
• 75g / 3oz tinned salmon: 17 mcg
FYI Delicate folic acid in foods is destroyed by overcooking, so cook in a covered pan with the minimum amount of boiling water. Try to eat vegetables lightly steamed, microwaved, or raw.