Spring is here! Starting today, days are getting longer, and we can spend more time in the sun. One of the benefits is that our body, cool factory that it is, can manufacture a very important vitamin just from our skin getting exposed to sunshine – vitamin D.
In the past few years, there has been a huge growth in vitamin D supplement sales. Why would anybody by supplements for something that is available for free? The answer is not so simple…
What you need to know:
First, a bit of a shocker: Vitamin D is technically not really a vitamin. According to author and nutrition professor Marion Nestle of NYU:
Vitamin D is weird because it is not a vitamin. Vitamins are chemicals found in foods that our bodies cannot make. But hardly any natural foods contain this particular chemical. Plants have none. Meat has little. Wild fatty fish like salmon have reasonable amounts, but farmed fish have much less. Fish liver has enormous amounts, but nobody eats it. We call this chemical vitamin D only because it was discovered at the same time as other vitamins. Read more…
So what is vitamin D?
It is actually a hormone that our body produces as a result of complex chemical reactions triggered by sun exposure. Vitamin D is critical for proper bone health. It helps calcium get absorbed in bones and strengthen them. But as a hormone, it probably has a few additional uses in our body.
The FDA currently recommends 400 IU (international units) of vitamin D per day. A brief exposure to sunlight can create 1000-2000 IUs, so that should be enough. Unfortunately, this is not always true. If you live in Northern states, the suns rays are much weaker in the winter. In addition, most of your skin is covered so you are not absorbing much sunshine. If you have dark skin, you are also going to be absorbing much less sunshine. And if you apply sunscreen, no hormone D either…
Additionally, some scientists are challenging the FDAs daily value of 400 IU, stating that it should be bumped up to at least 1000-2000 IU.
In this report, the IOM proposes new reference values that are based on much more information and higher-quality studies than were available when the values for these nutrients were first set in 1997. The IOM finds that the evidence supports a role for vitamin D and calcium in bone health but not in other health conditions. Further, emerging evidence indicates that too much of these nutrients may be harmful, challenging the concept that “more is better.”
So, should you be taking a vitamin D supplement?
In the past we were strongly opposed to this. Our philosophy is “get nutrients from food”. Unfortunately vitamin D is very hard to come by from food sources, and if sunshine is an issue, one could potentially be at a deficiency. Science is still trying to sort out how to standardize the measurement of vitamin D levels in our bodies, so it is also difficult to assess if you are deficient or not.
Our recommendation: consult with a dietitian or a physician to assess you and your family’s specific needs. If you are taking vitamin D supplements, take your daily pill / chewable candy at mealtime, as vitamin D is fat soluble.