Fill in the gaps with the correct words.

Vitamins can thus be looked at as a ... ingredient in the long-term ... of our health. Vitamins are divided into two main forms — water-soluble and fat-soluble. The fat-soluble ... , including A, D, E, and K, are absorbed by our body with helping fat, and they are ... in body fat. We do not need to take these vitamins daily, and it is usually possible to ... adequate amounts in our body through a normal, well-balanced ... . But for the same reason, it is possible to overdose on these vitamins by taking too many as ... . In which case, they can build up to toxic levels and actually cause ... to the persons who take them.