Swedish Nutra Vitamin C & D3 (500ml). Swedish Nutra Ireland. Vitamin C+D3 and Zinc are well known for their role in being super immune boosting vitamins/nutrients. Zinc helps your immune system and metabolism function. Zinc is also important for wound healing and your sense of taste and smell.. Vitamin C is essential for the reduction of tiredness & fatigue. Your body is unable to produce Vitamin C so taking a supplement is an effective way to boost your intake. Vitamin D is the sunshine vitamin and is known for its mood boosting properties. Zinc is necessary for the production of white blood cells – our immune army