What is all the hype all about and is it real? Originally, we were told that Vitamin D helps prevent thinning of the bones. More recently is has been touted to be a panacea for just about everything. It helps boost the immune system and mood, helps with muscle weakness, fatigue, prevents cancer/heart disease/diabetes and even helps slow down the aging process. So whenever one supplement does all this, I think we should be a little skeptical.
What does Vitamin D do? It helps your intestines absorb calcium. Without Vitamin d, your intestines can only absorb 10% of calcium from the diet; with it your body can absorb about 40%. Your body needs calcium to make your bones strong. Without enough calcium, your bones will start to thin, soften and can bow outward (known as Rickets in children) and can increase fractures in older adults.
Many vitamins must be consumed from different types of foods because your body can’t make it. Not Vitamin D. Vitamin D is made in our skin when exposed to sunlight and then converted in the liver and kidneys to usable forms. Vitamin D is found in certain specific foods as well. Since certain states have long winters and less exposure to sunlight, the federal government has required that Vitamin D be fortified in certain foods like milk, yogurt and orange juice to prevent diseases like Rickets. This disease is pretty much nonexistent in modern times because of fortified foods.
So why did experts think Vitamin D was so useful for so many things. Researchers did observational studies where they looked at people who took supplemental Vitamin D and found that they were less likely to have certain cancers, hypercholesterolemia, hypertension, heart disease, fractures and a myriad of other chronic illnesses that are common in our modern world.
I thought Vitamin D was just supposed to help with bone health, so how did it help with everything else? In these observational studies, the individuals decided whether they took additional Vitamin D or not. The people that were more likely to take theses supplements were more likely to be healthy, i.e. exercise regularly, eat healthily, and thus less prone to chronic diseases like heart disease and diabetes. When randomized controlled trials with Vitamin D were done (the researchers picked who got Vitamin D and who got a sugar pill), the results were quite different. Most of those studies did not show any benefit in the group that received Vitamin D supplementation. Some even found that Vitamin D supplementation may cause more harm: high levels of Vitamin D could cause weakness (and increase falls causing fractures), vomiting, and kidney stones.
So, what does all this mean? First, Vitamin D is not a cure all despite what celebrities may tell you. Second, the most important way to stay healthy is to get your vitamins and minerals from actual food and not from supplements. Third, get some sunshine (just not too much!*) and stay active outside. This will boost your levels of Vitamin D and provide way more benefit than you realize. Talk to your provider and decide whether you need Vitamin D blood level testing. Remember 97% of people in the US have adequate levels of Vitamin D (from the sun and fortified foods) when the Institute of Medicine and US Preventative Services Task Force determined that blood levels above 20 nanograms are adequate. However, more than 50% of individuals were noted to have inadequate levels when certain commercial labs changed the necessary level to >30 nanograms to have an adequate amount of Vitamin D. Hope this helps to clear up the craze surrounding Vitamin D. It would be awesome if a single supplement in pill form helped cure everything, but for better or worse, the old adage still holds-if you want to be healthy, balanced diet and regular exercise trump supplements**. Have a good summer and get your vitamin D the old-fashioned way, by enjoying that Idaho sunshine while it lasts!
*Too much sunshine, particularly without the use of sunscreen, could increase your risk of skin cancer.
**Be sure to talk to your provider before discontinuing any recommended treatments.