In last Wednesday’s e-tip (“Fighting in your sleep”), I told you that the sleep hormone, melatonin, can actually slow the growth of breast cancer by as much as 70 percent. Please note that Dr. Wright recommends taking 2 mg of melatonin at bedtime (and not 20 mg, as written in the 11/29 e-tip).

If you’re concerned about breast cancer, maintaining adequate levels of melatonin could go a long way in keeping you healthy. Another powerful weapon in the fight against breast cancer is vitamin D.

Sometimes I think medical researchers invented the chicken-or-the-egg argument. They’re constantly posing questions about two coinciding health problems and which one came first. The problem is, they hardly ever seem to arrive at an answer. The latest example I came across was a report on a study published in the Journal of Clinical Pathology regarding vitamin D and breast cancer.

This particular study pointed out the link between low levels of vitamin D and incidence of breast cancer: The women in the study who had the most advanced cases of the disease also had the lowest levels of this essential nutrient. For those of you interested in the nitty gritty details, the researchers studied 279 women, 204 of whom had early-stage breast cancer, and 79 with advanced cases. They measured the serum levels of 25-hydroxyvitamin D in all of the women (see the “What is…” section below for more information on this form of vitamin D). The women with early-stage breast cancer had the highest levels of the vitamin (up to 184 millimoles/litre) while women with advanced cancer had significantly lower levels (a max of 146 millimoles/litre).

No news there: Dr. Wright has been talking about this for years. But the scientists conducting the study seem to think they’ve stumbled upon a research goldmine because, apparently, it isn’t known “whether the low levels of vitamin D among those with advanced disease are a cause or consequence of the cancer itself.” So what they want to know, and are hoping to get lots of taxpayer dollars to find out, is whether vitamin D is the chicken or the egg.

My question is this: Does it really matter? Either way, increasing your own levels of vitamin D can only help. And the best way to do that is to get enough sunlight. When the skin absorbs the sun’s UV rays it starts a chain of reactions that ultimately produce vitamin D. Dr. Wright’s general rule of thumb is to stay outside in the sunshine — without sunscreen (even SPF 8 blocks out at least 88 percent of the sun’s UVB rays) — until your skin starts to get just slightly pink. Then head for cover.

Of course, those of us that live in temperate zones need some extra help. Researchers have found that practically no vitamin D at all is formed in sunlight-exposed skin during the winter if you live north of 35 latitude (which is about the equivalent of Los Angeles and Charlotte, NC). So Dr. Wright recommends taking 2,000-3,000 units of vitamin D in supplement form each day.