10 Ways Your Body Is Telling You You’re Running Low on Key Vitamins

“ Bruising on your legs” Possible deficiency: Vitamin C If you merely bump into something and wind up with an enormous bruise, consider if you're getting enough C. Surprisingly, it's on the list of nutrients Americans frequently fall short on, according to Health.gov. Vitamin C helps make collagen, which is involved in making blood vessels. Bruising often 'may be a sign that you have weakened capillaries that allow you to bruise,' says Small. What's more, stress saps your supply of vitamin C, meaning you may need more than you think.