vitamin D.
Seniors must make sure that their energy intake is high enough, as well as be sure to get adequate calcium, vitamin D, vitamin B12, vitamin C and iron supplements. Seniors most often lack vitamin D and iron. Vitamin D is a common deficiency, since seniors may spend less time in the sun or, when they are in the sun, cover up with sun-hats and clothing. While this is wise advice in many cases, this also means that the sunbeams will not reach the skin, and vitamin D cannot be formed naturally.
In these cases, Vitamin D can then be taken as supplement or also, refer to the guidelines for adequate time in the sun for children, as this also applies to adults and seniors (stay outdoors, baring your hands, arms and face for about 15-20 mins during the day.)