Vitamins are an essential part of any diet, but can they help you maintain a fasting state? The answer is yes, as long as you get the right type of vitamins. Multivitamins won't break the fast, but some of their components may not be absorbed very well on an empty stomach. Other supplements, such as vitamin D, omega-3, or iron, should be taken on an empty stomach or they are unlikely to break the fast. Vitamin C is an essential vitamin for proper immune function and B vitamins are a group of 8 water-soluble vitamins that play an important role in energy production, metabolism, hematopoiesis (blood cell formation), cognition, nerve function, hormonal balance, and much more.
It's best to cover vitamin and mineral loss by eating a nutrient-rich diet, but supplements may be necessary. A multivitamin may not have a calorie label, but many of the nutrients it contains are better absorbed with food. These supplements and multivitamins don't contain added sugar or calories, so you can safely take them during your fasting period without having to break your fast. However, too much of certain vitamins can cause harm (too much vitamin C can cause kidney stones; too much vitamin E can cause blood clotting problems).
If you are not already taking vitamin supplements before fasting and eat a wide variety of healthy foods during your meal periods, you probably don't need to start taking supplements. Creatine can help support maximum physical exertion during high-intensity activities such as lifting, jumping and running. In previous studies with overweight people who fasted for more than a year in a row, they were usually supplemented with a multivitamin. Eating fewer calories on an empty stomach may mean you're also eating fewer vitamins and nutrients.
If you still disagree with taking vitamins while fasting, keep in mind that a few grams of fish oil won't break the fast. Ultimately, it's important to understand what breaks a fast and how to maintain a functional fasting state.