Yes, vitamin A has been shown to inhibit the action of vitamin D,¹ however, vitamin A is obviously an essential nutrient.

In the 1930s, research showed cod liver oil to dramatically reduce the incidence of colds and respiratory tract infections. However, more recent research has been much less promising. The difference is believed to be a result of older forms of cod liver oil containing more vitamin D in conjunction with less vitamin A.²

For example, modern cod liver oil tends to contain 400-1,200 IU of vitamin D and 4,000-30,000 IU of vitamin A. This amount of vitamin D is less than what tends to be naturally found in the body while the amount of vitamin A is much greater.² This is obviously a considerable imbalance. In contrast, cod liver oil made with naturally existing levels of vitamins would contain something more like 30-60 IU of vitamin D and 3,000-6,000 IU of vitamin A.²

In my opinion, an even greater concern regarding cod liver oil and fish oil is their likeliness to contain oxidized fatty acids. These oils contain polyunsaturated fatty acids which are already susceptible to oxidation without the help of the processing that they go through.

Regardless of whether the concern is excess vitamin A or lipid oxidation, common sense dictates that it’s best to obtain vitamin D and vitamin A in the ratios that they naturally exist in which can be achieved by eating the whole foods that contain them (seafood, organ meats, etc.) and getting adequate exposure to sunlight.

1. Johansson S, Melhus H. “Vitamin A Antagonizes Calcium Response to Vitamin D in Man.” Journal of Bone and Mineral Research. 2001. 16(10):1899-1905.

2. Cannell JJ, Reinhold V, Willett W, Zasloff M, Hathcock JN, White JH, Tanumihardjo SA, Larson-Meyer DE, Bischoff-Ferrari HA, Lamberg-Allardt CJ, Lappe JM, Norman AW, Zittermann A, Whiting SJ, Grant WB, Hollis BW, Giovannucci E. “Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic.” Annals of Otology, Rhinology, and Laryngology. 2008. 117(11):864-870.

I hope your vitamin D level of 81 is in nmol/l and not ng/ml. If so, that is indeed a level to be proud of. Otherwise, it might be on the high end and would be worth looking further into.

The UVB level is dependent on the bulb, and since bulbs are replaceable, there isn’t necessarily any association between the bulb and the bed. I don’t know if it’s a good idea to go for the bulb with the most UVB. I’d prefer to use a bulb that matches the spectrum of natural sunlight as closely as possible, and I think natural sunlight has less than 2% UVB. As you seem to have experienced, most people who work at tanning salons probably don’t know anything about the bulbs or ballasts, but it should at least be relatively easy to get reliable information on the bulbs. If you can at least find out the make and model of the bulbs and bed, you can do your own research. Unfortunately, I don’t have any specific brands or models to recommend.

A question that you may or may not be able to answer – Do you know which beds have the highest UVB and safest electronic ballasts (not magnetic)? I’ve requested from the salons I go to for the beds that meet that criteria but have to admit that I’m not sure if I trust that they know what I’m talking about. Maybe if I get in touch with the manufacturers of these beds, they will let me know who purchased them. I know Dr. Mercola sells the Sun Splash but that’s an investment I am unable to make at this time.
Thanks again for your research.

It’s a tough choice. If I were in your situation, I would add more seafood to my diet to increase vitamin D intake naturally, and instead of taking a large dose of a vitamin D supplement weekly, I would take a smaller dose daily. In conjunction with the seafood and the fact that it is possible for excessive amounts of vitamin D to be harmful, I’d also probably take quite a bit less than 7,000 IU which is about what your dosage amounts to per day. I would stick to this for a few months and retest before considering the tanning bed. If you do choose to use a tanning bed, try to find one that uses electronic ballasts instead of magnetic ballasts to reduce your exposure to electromagnetic radiation.

This is just my own preference and reasoning. Your doctor might have a good reason for prescribing what he did.

I completely agree with your natural perspective! I don’t know much about what goes on at nursing homes, but it would be a shame if they deprived their residents of such a simple, cost effective, and enjoyable way to improve their health and happiness. I suppose the mainstream fears associated with sun exposure would be the primary cause for this, and the fact that sun exposure can cause reactions with a number medications doesn’t help much either.

I am a believer in supplements as well, but I use them as little as possible. Although most people consider supplements to be natural, it really depends on one’s interpretation of what this means. While supplements are usually natural in the sense that they are not artificial chemical compounds, they are unnatural in the sense that they don’t come directly from nature and are pretty far removed from whole foods.

The light that comes from tanning beds is clearly not natural. However, the concept is not much different in my opinion than oral supplementation, but few people see it this way. I think this is an interesting topic, and although it’s a from a slightly different perspective than what I normally write about, I think it’s good to have some variety and get people thinking.

It seems to me that the preferred source of vitamin D is through production from the skin, and as such, I think it’s possible that artificial light could be a more appropriate source of supplementation than a dietary capsule. It can even be argued as being more “natural” because it provokes the body’s inherent mechanism for producing it’s own vitamin D. This is what inspired me to write about tanning beds, although I intended it to be more of a discussion than a recommendation.

Where my “natural bias” applies is in the fact that I think it should be a priority to get vitamin D from natural sunlight and not rely on supplementation regardless of whether it’s from a tanning bed or a capsule.