Is there an advantage or disadvantage to consuming a serving of fruit a day via smoothie (just blended fresh raw fruit and water no other additives)?
No, there is no real disadvantage to consuming blended fruit vs eating whole fruit. As oppose to juicing, when you blend fruit you still leave all the fiber intact in the fruit. The fiber helps slow the digestion of your smoothie which means the fruit sugar is absorbed more slowly which in turn stops your insulin levels from rising sharply. One advantage of making smoothies is that some studies have shown that blending/juicing can improve the absorption of nutrients from the fruit. For your reference, some vegetables are more effectively processed when raw and blended, whilst others need to be cooked before eating.