I’m finally beginning to see the light at the end of the (low motivation, very fatigued) tunnel. I went to see Dr. W, my general practitioner, on Monday and had a complete blood panel done. Dr. W suggested we look at the usual suspects (iron, vitamin B, thyroid hormone). I asked her,”What if the tests come back and there’s nothing obvious?” I was a bit afraid that it was all in my head. I mean, who DOESN’T feel tired these days? If that happened, she recommended that I “top everything off” with a daily multivitamin. She said it wouldn’t hurt and could only help if I was just slightly (but not detectably) deficient. So, I dutifully went to the store and picked up a women’s multivitamin and have taken one everyday. So far, so good.
The great thing about Kaiser (my healthcare provider) is that they believe in transparency. They emailed me the results as they came in, along with the normal range and a link to find out more about each test. I still need to consult with Dr. W, but from what I understand, I’m very deficient in vitamin D and magnesium, and my ferritin levels are low for a runner. Everything I’m about to write needs to be predicated with this disclaimer: I may be a doctor (Ph.D.), but I’m not that kind of doctor (M.D.), so everything I say should be taken with huge grain of salt. I will say that I’ve found the NIH’s Office of Dietary Supplements page to be extremely informative.
From what I’ve read, it’s very difficult to accurately assess magnesium levels, so I’m not going to focus on my supposed magnesium deficiency (for now). My vitamin D levels are substantially lower than the recommended levels, and that wasn’t completely surprising given our rainy, dark winter. The best source of vitamin D is sunlight – it’s recommended that everyone gets 15-30 minutes of full sun exposure 3-4 times a week. Since I’ve been running early in the morning, a lot of my winter runs were in the dark or just at dusk. Fortunately, this past week has been much sunnier, so I’ve been working hard on “making” vitamin D. The confounding thing is that the symptoms related to vitamin D deficiency (mostly bone weakness and osteoporosis) aren’t the symptoms that I’ve been having (profound fatigue). Still, it’s good to know that my vitamin D levels are low so I can try to increase my bone strength and hopefully stave off any stress fractures.
The ferritin is the most interesting result to me as a runner. Ferritin is the protein that stores iron, while hemoglobin is the protein on your red blood cells that carries iron and oxygen around your body. My hemoglobin levels are normal, but my ferritin levels are low. Actually, I’m technically on the low range of normal (25 ng/mL), but according to this post, runners are recommended to have 40 ng/mL. According to the same article, as many of 50% of female runners are iron deficient, due to low iron intake (in their diets), menstruation, and loss through the GI tract. Moreover, iron is required for more than just oxygen transport, it’s also needed for oxidative metabolism. Therefore, runners who have low iron stores may suffer in performance due to multiple mechanisms.
Before I start downing iron supplements, however, I want to talk to Dr. W. There are risks involved in having too much iron and vitamin D. For now, I’m playing it safe and taking a daily multivitamin. It might all be in my head, but I’m already feeling better – my runs this week have been pretty decent. In particular, my 9.7 mile trail run this morning felt substantially better than many of my long runs of late. Hooray!