One of the most important roles of vitamin D is in calcium absorption. Vitamin D and calcium are both known to decrease with age and deficiency of either can lead to osteoporosis, among other health problems. You can get your calcium from veggies such as kale, collards, sweet potato and butternut squash, as well as dried figs, dairy and dairy alternatives, and fortified orange juice.
Another good reason to keep your vitamin D levels in check is the telomere, a part of your DNA strand which researchers believe may be a biomarker for aging. Experts believe that vitamin D is associated with the length of the telomere, which is known to shorten with age. Essentially, the longer the telomere, the better.
An easy way to get vitamin D is to spend 5 to 30 minutes in the sunlight each day between 9 a.m. and 3 p.m. There are also a few vitamin D sources that can be consumed, including swordfish, salmon, tuna, dairy, fortified breakfast cereals, fortified orange juice and eggs, which have vitamin D in the yolk.