As well, many of us live in northern climates with low levels of sunshine, particularly in the winter months. It may be a good idea to have your blood tested for vitamin D levels every once. While our ancestors lived outdoors and didn’t wear much clothing, in the modern world, this has changed. Today, most people work indoors and wear clothes much of the time. Most of the time, these diet plans are extremely unhealthy, not allowing people to get all the nutrients their body needs. Another important thing to consider is that our ability to absorb B12 decreases as we get older. This means everyone needs to be concerned about their B12 intake, especially older adults.