Vitamin D - Naturopathic Medicine Dr. Lynn Mikel

Vitamin D

There is much information out recently regarding need for more vitamin D. The importance of vitamin D has been recognized by naturopathic doctors for some time. It is an important vitamin that works like a hormone in the body to direct bone growth, remodeling, and mineralization. It has many other roles in the body including regulating the immune system and inflammation. It plays a role in regulating cell growth, differentiation, and removal of abnormal cells. Vitamin D deficiency has been associated with osteoporosis and various autoimmune diseases as well as prostate, breast, and colon cancer. Very few foods contain vitamin D in high amounts.

Foods containing Vitamin D
iu per serving

Cod liver oil, 1 tablespoon 1,360iu
Salmon, cooked, 3.5 ounces 360iu
Mackerel, cooked, 3.5 ounces 345iu
Tuna fish, canned in oil, 3 ounces 200iu
Sardines, canned in oil, drained, 1.75 ounces 250iu
Milk vitamin D-fortified, 1 cup 98iu
Margarine, fortified, 1 tablespoon 60iu (not recommended)
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40iu
Egg, 1 whole (vitamin D is found in yolk) 20iu
Liver, beef, cooked, 3.5 ounces 15iu
Cheese, Swiss, 1 ounce 12iu

Foods do not adequately supply this important vitamin need. Most people meet this need through sunlight exposure. UVB light waves convert a cholesterol molecule in the skin to a pre-vitamin D3 which then gets modified once in the liver and again in the kidney. Sun exposure to skin is limited in our area by many gray days. It is also limited by our northern latitude where we are further from the sun. Other factors that limit sun exposure are use of sunscreen, smog, and skin pigment.

The best way to test for adequate vitamin D levels is through blood work analysis. The form of Vitamin D to test for is 25(OH)D which is the best reflection of total D vitamin from food, sun, and supplements. Optimal levels are 50-55 ng/mL. I frequently include this when I perform lab work. Most frequent levels found are between 15 and 28. This indicates most people here in Seattle need some additional vitamin D.

The body stores the vitamin in fat cells therefore, if supplementing, could potentially achieve toxic levels. However, patients taking fish oil regularly and even those supplementing 400 to 1000iu for several months or years are still far below optimal levels. My recommendation is to get your levels tested and use a quality supplement of Vitamin D3 not the synthetic Vitamin D2. Current recommendations of 200iu to 600iu are generally much too low. New recommendations of 2000iu to 5000iu may be needed according to some studies. Once supplementation has been started for a few months retesting is recommended to assess levels. Toxicity is possible for an adult at levels over 200 ng/mL. Symptoms of toxicity are nonspecific such as nausea, vomiting, loss appetite, constipation, weakness, weight loss, confusion, and heart rhythm abnormalities.

Dr. Mikel would be happy to test your levels and provide safe recommendations and supervision in your use of vitamin D. Many people who are deficient and start supplementation of D3 report improvement in mood, decrease musculoskeletal pain, improved energy and outlook!