Vitamin D – Too Much Of A Good Thing?

Vitamin D has gotten a great deal of media attention in the past decade. It has been said to be beneficial for health concerns including osteoporosis, depression , and even cancer prevention. Should you be supplementing too? And how much should you take?

First, remember that there is a reason why vitamin D is often referred to as the sunshine vitamin. Our skin, after the exposure to UVB light has the ability to produce its own vitamin D. Studies have shown that the exposure of skin on our hands arms and face to natural sunlight for about 15 minutes, three times a week, would suffice. Why, then, would anyone need to take it orally?
Many people, especially those living in the northern hemisphere tend not to get enough sunlight (thanks to the long winters). Second, with age, our skin’s ability to produce vitamin D decreases. Lastly, among those people who do get adequate sun exposure, many are vitamin D deficient. The cause of the last category can be complex, as the synthesis of the active form of vitamin D need the help of the liver and the kidneys. If you have chronic liver or kidney related conditions, you are likely not getting enough vitamin D despite adequate sunlight exposure. Severe vitamin D deficiency leads to rickets, osteomalacia and muscle weakness. Although these are rare now that many food items we eat are fortified with vitamin D, less than optimal levels of vitamin D have been linked to fibromyalgia, depression and chronic fatigue syndrome.

If you are someone who does require vitamin D supplementation, it is important to note the following. First, the form of vitamin D that you take is important; to maximize the effect, the active form (vitamin D3) is preferred. However if you are on prescription vitamin D (which is the less potent form, Vitamin D2), and you are at risk of cardiovascular events, you should consult a health care provider before switching.

Second, the dosage of vitamin D is also crucial. Not everyone requires the same amount of vitamin D intake. Too much vitamin D has a variety of side effects. Most of these result from the mechanism that helps to prevent osteoporosis . Vitamin D helps the body deposit calcium from the blood stream out to body tissues. This deposition can be where we would like for it to be- bones, or places where it shouldn’t be, such as kidneys, arteries. Too much vitamin D will cause inappropriate amounts of calcium deposition, causing the latter scenario. Calcium deposition onto soft tissue can lead to kidney failure and even cardiovascular events.

The take home message is this; it would be ideal to get vitamin D from sunlight exposure. If this is not possible, vitamin D supplementation may be required. For those that are taking oral vitamin D, it would be best to consult a health care provider in order to achieve the greatest efficacy without compromising on safety.