Back in the day, vitamin deficiencies were pretty much a part of life. Before refrigeration, nutritional science, and modern farming, certain foods simply weren’t available to eat.

In the modern United States, we need to worry about these problems a lot less, but that doesn't mean they've been completely eradicated. In fact, certain medical conditions and poor diet can combine to create vitamin deficiencies you may not even know you have.

Here’s how to get a few of the most commonly-missed into your diet. Don’t fancy cooking? Grab something good with Foodpanda delivery.

Folic acid

Folate and folic acid are most often associated with their importance in early pregnancy, and they are essential in the prevention of congenital disabilities. However, that doesn't mean they're not necessary for everyone else! Millions of people across America are still not eating enough fruit and vegetables (especially the leafy green ones), and these are vital sources of folic acid. Alternatively, watch out for enriched products such as bread and cereals, which are required by the FDA to be fortified with folic acid.

Vitamin B12

Vitamin B12 is key for maintaining healthy blood and nerves. Unfortunately, as we age, our bodies become less able to process B12 as the acid levels in our stomach decrease. We can eat all the B12 we want, but our body is simply less able to process it. People over the age of 50 should consider supplements.

Other people at risk of B12 deficiency, because it's found in meat, fish, eggs, milk, and dairy, include vegetarians, vegans, and people with other food absorption disorders such as Crohn's disease. Vegans can supplement their diet with fortified breakfast cereals. Check for B12 on the box.

Vitamin D

An essential vitamin for healthy bones, vitamin D is unusual among the vitamins in that we don't get much of it from food. Instead, we get the majority of our vitamin D from the sun. This means that people who are most at risk of vitamin D deficiency are people who live in smoggy, polluted areas, use high-factor sunscreen, have darker skin, or just don't get a lot of sunshine. As a lot of these causes are environmental, it's sometimes impossible to solve the problem by just 'getting more sun.'

Fortunately, many food and drink products are now fortified with vitamin D. Look out for enriched cereals, milk, and juices. You can also get your fix in oily fish such as salmon and tuna.

Iron

Another essential for anyone looking to become pregnant (or who are pregnant already), iron helps the blood to transport oxygen around the body. Without it, we feel tired and lethargic. Iron deficiency can lead to a condition called anemia.

The best way to get more iron into your body is to eat it. Lean red meats, seafood, and poultry are all packed with it. Beans, spinach, and pulses will do the job for vegetarians and vegans. Eating iron in combination with vitamin C-rich foods is also useful as this helps the body absorb the iron.