I wouldn't say it's a matter of life and death. :o) You may find it at a health food store...depends on where you live and what they may have available. See if they could order it for you...Do you have any iron .Also depends on how much you were going to be making up...if it's a 6 months supply I'd consider getting some, but if it's just for a month or two...don't worry about it. I just think it rounds the formula off a bit...but again, it's not earthshattering. (If you have some extra of one of the other ingredients, just add more of that this time around.)