I’d keep some around for backup in case something goes wrong with my food stores out at sea. Shit happens out here and I’m either alone or the responsible party. I’ve been lucky, though. The worst was when I had to go four days on a small tin of salted anchovies and box of crackers.
It was hardly a starvation situation, but it was as close as I ever want to get. I had gone for what I thought was going to be a day-sail in an old, stripped-down, 33-foot Morgan out of Key West and was blown out to sea by a sudden squall coming out of the north-east. I had no stores on board and a case of bottled water. I had one hand-held UHF radio with a range of only a couple of miles on a good day. I was inexperienced and overconfident—in a word, an idiot.
Never again. I am now huge on prep and never leave the dock without a cache of canned goods, including a case of Ensure, that I keep for emergencies. I also carry at least a couple hundred gallons of freshwater in my tanks at all times. If the water ever runs out, I have a water maker. Those nutrient pills you describe, if they kept well at outside temperatures of 90F, or so, would be perfect as an emergency store as they could provide weeks of food, if necessary, taking up very little space in the lazarette.
Otherwise, I’m too much of an unapologetic trencherman to settle for a pill to satisfy my daily nutrient requirements. A gourmand’s needs, unlike a gourmet’s, are simple, but voracious. A pill won’t do it.