As I was thinking about New Year's traditions, I only really had two that came up and since last year I talked about the Polar Bear Plunge, this year I thought about eating black eyed peas, which apparently is more of a Southern thing so I don't know if y'all do it out here too (written when I was living in California).
Peas always come to mind these days as a source of protein (1 cup has as much as 2 oz of beef or salmon or chicken) and iron (4 mg or about a quarter of your daily allowance). The iron thing actually comes up a lot when we start talking about iron deficiency.
Iron is essential for making hemoglobin and myoglobin, which transport and use oxygen from your lungs to all your cells. Most of your body's iron is stored in red blood cells and muscle cells. A small amount is used for maintaining immune system function and building proteins and collagen and the rest just hangs out in your blood as ferritin, like suitcases just going around the carousel at the airport until needed. Most men have stored iron to last 3 years, whereas women only have enough for about 6 months, usually due to blood loss during their menstrual cycle.
When you run out of ferritin, you have iron deficiency. If you don't have enough iron stores to replace red blood cells (as they die off naturally after about 3 months), then you develop iron deficiency with anemia. As mentioned, very common to see happen in pre-menopausal women, especially those with heavier menstrual cycles. For men and post-menopausal women, blood loss is usually more occult and we typically worry about something bleeding slowly in the GI tract to cause the red blood cell loss. Much less commonly it can happen from things like severe nose bleeds or cancers that keep your bone marrow from working. And of course blood loss from accidents too. Blood donors typically lose about 20-25% their iron with each donation.
Low iron levels can cause a lot of different symptoms like fatigue, weakness, headaches, dizziness, restless legs - a whole myriad of stuff so that oftentimes its one of the first things we check when people aren't feeling well.
So how do you keep your iron stores up? Typically through diet. Ideally most people should be getting 1.8 mg of iron absorbed per day, the catch being that only 10-30% of the iron you eat is actually absorbed (and some people think your gut needs 48 hours to reset after it maxes out on the amount of iron it can absorb). To make up for that, the RDA for men and postmenopausal women is about 8 mg per day and for pre-menopausal women 18 mg.
There's a long list of foods with iron in them - typically the ones that aren't meat are thought to have a little more difficulty being absorbed without vitamin C, but if you're a vegetarian or vegan you're probably already getting enough vitamin C to aide in the absorption. Too much iron in the gut though can cause constipation so don't go overboard.
Here is a good list of iron rich foods for you to THRIVE on!