Vitamin D and Magnesium are impressive supplements. They both combat a wide array of diseases and conditions that plague modern societies. But I would have to say broccoli, especially in the anti-cancer arena, is king. In fact, as you study the research on this vegetable, it is almost mystifying that one vegetable could do so well against so many conditions. It is, simply put, Mother Nature's Special Forces to try to protect you from the enemy.
I should mention that any cruciferous vegetable has the same superpowers. Therefore, consider cauliflower and cabbage your special friends as well. And don't forget to tell the Little Woman that broccoli will 1) lower her levels of the "bad estrogen" and 2) offer substantail protection against breast cancer. (Among other things, it causes breast cancer cells to self-destruct.) You might save her life and score a few points while you're at it. And, if you're like most of us, you really need to score a few points!
NOTE: Broccoli is easy to cook. Simply grab a coffee cup/mug and put a third or half of an inch of water in the bottom. Then pull out some fresh broccoli and pull off enough florets to fill up the cup. Put it in the microwave for about 2.5 minutes and the steam will cook the broccoli nice and soft. Add a little salt and you are good to go. And if you're one of those people who just can't stand the smell or taste of broccoli, then you've still got no excuse: just eat cauliflower and cabbage instead. All of these are in the cruciferous vegetable category and share similar properties.
The bottom line, though, is that one way or another you need to be cooking and eating this at least four days a week. Here's just a few reasons why:
1. Stroke. Broccoli, in a Journal of the American Medical Association issue, lessened the risk of stroke more than any other vegetable or fruit studied! .
2. Cataracts. Broccoli decreases your risk for cataracts.
3. Herpes and Shingles. We have already covered that broccoli's Indole-3-Carbinol (I3C) protects against herpes and shingles viruses.
4. Colorectal Cancer. Animal studies have shown broccoli to be protective against colon cancer. 
5. Prostate Cancer. Broccoli's allyl isothiocyanate causes prostate cancer cells to self-destruct. 
6. Anti-carcinogens. These same isothiocyanates (ITCs) are recognized in multiple studies as powerful anti-carcinogens. 
7. Another isothiocyanate (ITAC) called phenethyl isothiocyanate (PEITC) blocked tumor promoters. 
8) Apoptosis. Many studies show IECs induce apoptosis, i.e. cause cancer cells to self-destruct.
9) Cardiovascular Protection. Broccoli has several studies showing that it is heart protective as well.  Scientists recently discovered that this may be because sulfuraphane increases the activity of a protein called NRf2 that is known to be inactive at sites of arterial plaque buildup. 
10) Prostate Cancer. Broccoli has long been known as protecting the prostate from cancer. 
11) Lung Cancer. Broccoli slows the progression of lung cancer  and improves COPD.
12) H. Pylori and Stomach Cancer. One kind of ITC in broccoli has been found to be extremely damaging to H. Pylori, the bacteria that often causes ulcers and stomach cancer.  One 2009 study verifies this and found that those who ate broccoli sprouts had significantly reduced levels of H. Pylori and this will undoubtedly greatly reduce one's risk of stomach cancer. 
13) Tongue (and Prostate) Cancer. Sulfurophane has been found in the laboratory to fight metastic tongue and prostate cancer cells. 0]
14) Bladder Cancer. You got the idea by now: broccoli protects from bladder cancer as well.
And, trust me, this is just scratching the surface of broccoli's power! Broccoli (and other cruciferous vegetables) have also been found to aid in DNA repair. In other words, even if your DNA does get damaged the I3C in broccoli has been found to activate proteins that repair DNA.  So broccoli isn't just about defense - it's about offense as well.
So whether you love the taste of broccoli or hate it, figure out some way to consume it - it will very likely save your life someday.
1) JAMA, 1999, 282:1233-1239
2) J. Nutr, 2002, 132:307-309
3) Carcinogenesis, May 2003, 24(5):891-897
4) Cancer Res, 1994, 54:1976s-1981s; J Nutr, 2001, 131(suppl):3027s-3033s;
5) Cancer Res, 1998, 58:4102-4106
6) "Broccoli: A Unique Vegetable That Protects Mammalian Hearts through the Redox Cycling of the Thioredoxin Superfamily", Jan. 23 2008 issue of ACS' Journal of Agricultural and Food Chemistry.
7) J Natl Canc Inst, 2000, 92:61-68; Cancer Epidem Biomarkers Prev, 2000, 9:795-804
8) Cancer Res, 2005 Sep 15, 65(18):8548-8557
9) Cancer Prev Res, April 1 200910) Intl J of Cancer, 2008, 123(6):1255-1261
11) Brit J of Cancer, 2006, 94:407 426, Published online 24 January 2006, "BRCA1 and BRCA2 as molecular targets for phytochemicals indole-3-carbinol and genistein in breast and prostate cancer cells"
12) Cancer Prevention Research, Apr 1 2009, "Dietary Sulforaphane-Rich Broccoli Sprouts Reduce Colonization and Attenuate Gastritis in Helicobacter pylori Infected Mice and Humans"