If your goal is to build muscle, you better make sure that you have enough vitamin D in your body. One of the main functions of vitamin D is muscle growth. Believe it or not, taking a shower every day can cause a vitamin D deficiency and lead to muscle loss, weakness and ultimately a lower metabolic rate. It’s true!

I learned this valuable lesson from Dr. Peter Osborne, author of No Grain, No Pain, who gave a talk on the subject earlier this year. Here are some of the highlights from that discussion:

• One of the main reasons for vitamin D deficiency involves over-hygienic people who constantly wash their hands and take too many showers. Even bronzed individuals who live in a sunny climate can be severely deficient in vitamin D if they wash too often.
• You’re not going to get much vitamin D from your diet; liver and mushrooms are two of the best sources, but other than that not much is present in food. Even if food is fortified with vitamin D, it’s usually the nonactive form of D2, which will not have any real hormonal impact. Furthermore, the dosages are so low, it’s like “trying to spit on a forest fire!” It won’t have a significant impact on the body’s needs.
• We make vitamin D primarily from sunlight exposure. There’s a form of cholesterol on our skin that sits as an oil and when UV light hits that cholesterol, it converts it into vitamin D.
• The vitamin D that sits on our skin takes 16 hours to get absorbed into the bloodstream, and then it has to go to the liver and kidneys before being metabolized into its active form. There are many processes that have to happen, and your liver and kidneys better be healthy to make it happen!
• Showering every day and using soap on your body will remove the oil on your skin and some of the vitamin D along with it. So even with adequate sunlight exposure, vitamin D absorption may be compromised due to frequent showers.
• The germ theory of disease has made people so afraid of germs that they forgot about balance. You don’t need to constantly wash your hands or take multiple showers every day. All of this can be contributing to disease, especially autoimmune disease.
• Vitamin D regulates the response of the immune system. It tells your immune cells to calm down if they’re out of control, or else the situation becomes like “teenagers without parental guidance.” Think of a house party going on in your body and all the furniture gets destroyed. That’s the type of internal damage that can occur with a vitamin D deficiency, all because you’re too clean!

For Dr. Osborne’s full discussion on vitamin D, check out The Diabetes Summit. I highly recommend it.

Take-Home Message: Shower every other day or if you have to shower every day, then soap up only the “stinky” parts and let some of the oil on your skin sink in, especially the parts that get sunlight exposure. Also, make sure that you shower in the morning before you’re exposed to the sun. Don’t do it at night. Wait until the next day to give your body extra time to absorb the vitamin D while you sleep.

P.S. Here’s my challenge to any health-care practitioner that prescribes vitamin D in supplement form to their (non-infant) patients or clients.