What’s the Deal with Vitamin D? (Part II) -- By Conner Keyeski, APRN
In my previous post I discussed the health
benefits of vitamin D and how it affects different body systems. In this post I will discuss different sources of vitamin D and what I consider optimal vitamin D levels.
Exposing our skin to ultraviolet B rays from the sun is a great way we can increase our vitamin D levels. Factors that influence how much vitamin D we can actually get from the sun include age, skin type, geographic location and the time of year. One study showed that someone living in Florida with Fitzpatrick sun-reactive skin type III (darker white skin, tans after initial burn) would require 6 minutes of sun exposure to synthesize 1,000 iu of vitamin D in the summer and 15 minutes in the winter. On the other hand, someone living in Boston who would need 15 minutes in the summer and 29 minutes in winter to synthesize the same amount of vitamin D.
The downfall with sun exposure is weather conditions and the time of year can limit how much vitamin D we can get from the sun, and we often need more vitamin D than it can provide. Sun exposure comes with risks as sun sensitivity, and being exposed to too much can increase the risk for melanoma and other skin cancers.
There are some foods that contain vitamin D naturally, but the selection is limited. One of the best food sources of vitamin D is the fatty flesh and oils of fish like salmon, trout, tuna and mackerel. Animal sources like meat, organ meats, cheese and egg yolks also have vitamin D but are dependent on the animal’s diet. The best plant source for vitamin D is mushrooms, as they can synthesize vitamin D like humans through UV light exposure. Vitamin D is also added to many fortified foods including cow’s milk and non-dairy milk alternatives, cereals, fruit juices and yogurts.
Vitamin D supplements are widely available and made for people of all ages. As with most supplements, choosing an appropriate, high quality vitamin D supplement can be difficult. There are two types of vitamin D supplements, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is made from plant sources and the type that is used in fortifying foods. Vitamin D3 is the type of vitamin D that humans produce and also found in animal sources. An analysis of randomized control trials found that vitamin D3 raised levels more effectively and sustained those levels longer.
Two types of vitamin D can be tested with blood work, 25-hydroxyvitamin D (25-OH-D) and 1,25-dihydroxyvitamin D. 25-OH-D tests for the stored amount of vitamin D in the body and, because of its longer half-life and higher concentrations, it is a better indicator of someone’s vitamin D status. Normal vitamin D levels based on laboratory data ranges from 30-100ng/mL. For my patients I like to optimize levels in the 60-80ng/mL range.
I recommend people get vitamin D from all of the sources mentioned as each has benefits outside of just the vitamin D. Ideally, sun and food sources would be all we need, but the majority of Americans need supplementation to have adequate vitamin D levels and levels that improve their health.
_________ Conner Keyeski, APRN, NP, specializes in Holistic Primary Care for all ages, including illnesses, minor injuries, annual physical exams, and related health issues. Contact us today to set up your first (free) visit at 785/760-0695.