Vitamin D FAQ
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What is Vitamin D and Where Does it Come From?
Vitamin D is a fat-soluble vitamin which can take a number of different forms and plays a number of different roles throughout the human body, including bolstering the immune system, potentially helping to prevent various forms of cancer, and even reducing the incidence of depression.
If you know anything about vitamin D then you might be aware that it can be obtained through direct exposure to sunlight.
It is argued that the production of vitamin D through exposure to sunlight is a protective response by the body against potential toxicity. Because of the potential relationship between prolonged exposure to direct sunlight and skin cancer there are no official recommendations regarding how long you should be exposed to sunlight to obtain adequate amount of vitamin D.
What Types of Vitamin D Are There?
As mentioned above there are a number of different forms of vitamins D; however, the two most important forms that we will be looking at in this FAQ are vitamin D3 and vitamin D2, known as cholecalciferol and ergocalciferol respectively.
The former is what is produced by the skin as a result of exposure to UV-B rays from the sun.
Most of the health benefits that we will be discussing are attributed to the supplementation of Vitamin D3, so this is what we will be focusing on.
How Does Vitamin D Work and What are the Benefits?
Much of the scientific data regarding the health benefits of vitamin D supplementation are inconclusive, with the quality of data produced from many studies being of low quality generally inconsistent.
Although there is no solid evidence to suggest that supplementing with vitamin D can help to prevent or otherwise reduce the risk of cancer, it is argued that the low levels of vitamins D or hypovitaminosis D can worsen the status of cancer patients.
Vitamin D efficiency has also been correlated with higher incidences of osteoporosis, rickets, and an overall reduction in bone mineral density.
Taking all of this into consideration, there is little evidence to suggest that vitamin D supplementation is relevant in the context of prevention in otherwise healthy adults.
Who Can Benefit from Using Vitamin D and How?
When looking at any supplement it is important to take context into consideration.
The vast majority of medical studies that are conducted involve either average healthy individuals or those suffering from a specific medical condition; very few set the focus squarely on bodybuilders or athletes.
For this reason it is very difficult to determine whether or not vitamin D has some objective validity in the context of the supplement regimen of a hard training individual.
With this said, it can be anecdotally suggested that vitamin D supplementation is useful to bodybuilding because of the role that it plays in enhancing immune function and improving bone mineral density.
I Have Heard That Vitamin D Can Combat Depression, Is This True?
Depression is a complicated subject but there is some evidence to suggest that seasonal affective disorder or SAD is brought about by a vitamin D deficiency caused by a lack of sunlight during the shorter days of the winter months.
Further strengthening this argument is the fact that more northerly countries such as Greenland report higher rates of suicide than nations closer to the equator.
The jury is out on this however, but if you are suffering from a severe case of the “winter blues” manifesting in low energy levels and a dampened mood then it certainly can’t hurt to try supplementing with vitamin D providing you do so in a responsible manner.
Do Any Foods Contain Vitamin D?
The main food sources of vitamin D are:
- Oily fish such as salmon;
- Beef liver; and
- Egg yolk
There are very few major dietary sources of vitamin D, which is why it is so important to source it from either sunlight or supplements.
Does Vitamin D Have Any Side Effects?
Although no threshold has been officially established for vitamin D toxicity, the tolerable upper intake limit or UL is 4,000 IU per day for individuals aged 9 – 71.
Hypervitaminosis D is a term used to describe excessive levels of vitamin D within the body, and this can lead to a number of complications including nausea, kidney failure, weight loss, and abnormal bone growth likely due to hypercalcemia.
While there are some potential health benefits to be gained from supplementing with vitamin D it is important that you do not take it lightly and instead exercise caution by starting with a low dose and not using it consistently on a long-term basis.
As with any dietary supplement, we recommend that women who are pregnant or breastfeeding consult their doctor or physician prior to use. This also applies to people under the age of 18 and individuals who suffer from pre-existing medical conditions or who are taking any kind of prescription medication.
Note: We recommend speaking to a doctor before taking any supplements.
How and When Should I Use a Vitamin D Supplement?
The majority of people will use vitamin D along with other supplements, and for most athletes and bodybuilders this means taking them with breakfast.
Because of the fact that vitamin D is a fat-soluble vitamin it is advisable that you consume it with a meal that contains some fat to facilitate absorption and utilization.
How Much Vitamin D Should I Take?
Some individuals are more sensitive to the potential deleterious effects of vitamins D than others, so while a tolerable upper intake limit has been established it is advisable that you always adhere to the manufacturers guidelines on any vitamin D supplement that you purchase.
Choosing the Right Vitamin D Supplement
Choosing a vitamin D supplement need not be a complicated affair; just make sure that the product you use contains Vitamin D3 rather than D2.
If you are currently using a multivitamin then make sure you check it for its vitamin D content before purchasing a stand-alone D supplement because you will need to take your current supplemental intake into consideration in order to decide on an appropriate dosage.
Please note: This FAQ has not been written or reviewed by a doctor or medical professional and is therefore not to be used to prevent, diagnose, or treat any disease or illness. Nor should it be used as medical reference.