i don't know why your husband it getting leg cramps. there can be dozens of reasons but i can tell you that vitamin b12 doesn't cause them. he will need to discuss this issue with his medical provider to determine a cause. and a solution. remember that men can be stubborn about getting medical care so your encouragement is very important. i can't speak to the science or the research but i did not have leg cramp problems until i started taking b-12. i stopped taking it and have not had any leg cramp problems since. your husband is not alone in having a similar experience.
can b 12 cause leg cramps? . since my husband started taking b 12 he has been getting severe leg cramps