If you're following a low-carb diet, you may want to watch which cocktails you drink. You always add calories when you mix a drink with vodka, but depending on your mixer, you may or may not add carbs to your daily count.
Vodka has about 69 calories per ounce, according to Drinks Mixer. It does not have any carbohydrate content, but alcohol calories are "empty" calories like sugar, because alcohol doesn't have any nutrients.
You can keep from adding carbs to your daily amount by limiting what you add to vodka. The same goes for calories. Use diet soda, diet tonic water, club soda or other no-sugar, no-calorie options to keep from adding to your carb or calorie limits. Many flavored varieties of vodka have the same calorie count as the regular version.
You can gain nutrients such as vitamin C if you mix your vodka with vegetable or fruit juice. However, you'll also add calories as well as carbohydrates in varying amounts, depending on the juice you choose. Grapefruit juice adds 115 calories per cup, while passion fruit juice has 126 calories in a cup. Mixing vodka with a sugary soda increases your carbohydrate and calorie counts and further increases your intake of empty calories. A 12-ounce serving of ginger ale has 7 tsp. of sugar and 124 calories, while a 12-ounce lemon-lime soda has 9 tsp. of sugar and 148 calories.