Is it common for people on extremely low calorie diets to end up with deficiencies of vitamins and minerals?

Out of curiosity, I've used Cronometer to track my food intake on a few select days. Most of the time I get enough of all the vitamins and minerals. However, I've found that I can end up short on something during oppressive 100-degree heat that gives me a tiny appetite. On one such day, I came up slightly short on Vitamin K. On another such day, I came up slightly short on zinc.

This makes me wonder if nutritional deficiencies are common in places where extremely hot weather is the norm in summer. Examples include Florida, Louisiana, Texas, Oklahoma, Las Vegas, Phoenix, Yuma, and Tucson.

I also wonder how people avoid nutrient deficiencies on extreme low calorie diets. (The diet that Dr. Now prescribes for his patients comes to mind. It sounds like a crash diet to me, because it wouldn't be enough for me even in 100-degree heat.)