In the 1970's, 35mm SLR photography enjoyed a very good popularity expansion once Canon figured out a way to make a cheaper and lower-priced 35mm SLR than just about anybody else, and by the early 1980's, there was a HUGE explosion of 70-200mm or 70-210mm zoom lenses made by about 15 different Japanese-based lens manufacturing companies, and those lenses were "branded" by various stores, camera chains, and small-time "labels", often under multiple "labels. A famous one was Vivitar. Vivitar never actually manufactured a single lens; they contracted that out, and had many different makers for their multiple lenses. Well, in that era, with so much competition, it was found that adding a Macro mode was a sales feature. Just adding a couple of lines showing the closest focusing zone was enough....fill 'em with orange paint and the word "Macro" also in a colored Paint, and suddenly a lens that focused relatively close could easily be labeled as and marketed as a "macro zoom lens".
A real,
true macro lens almost always focuses to at least 1:2, or 1/2 life size. More commonly today, that is improved, and a macro lens will focus to 1:1, or life size. But on macro zooms, the range is usually around 1:10 to 1:5, which is a LOT LESS magnification than 1:1, or even 1:2. So...the words "macro zoom lens" from the 1970's until 2015 means basically a zoom lens that focuses a bit closer than what would be considered normal, but is pretty much not much more than marketing hyperbole. The word "Macro" on the barrel of a zoom lens do not mean much. Think of it more as a close-focusing zoom lens than a real, true, purpose-built macro lens.
One thing: adding a good-quality close-up lens, like the Canon 250D, or the Nikon 5T or 6T, or other high-grade, two-element close-up lenses (screw-in filters, basically, but with two lens elements and good multi coatings), can actually do pretty good macro work with a number of lenses.
An inexpensive 12 to 20mm extension tube, or even a cheapie teleconverter with the glass smashed out with a hammer to MAKE an extension tube, can be used with something like the Nikon D5100. SInce your camera uses only the central image zone, the results can be pretty acceptable to maybe even good. The best close-up lenses, when used with a good zoom, can produce pretty good image quality.
HERE is an inexpensive Nikon mount zoom with a macro focusing mode, constant, perfectly round max aperture of f/5.6, and which works exceptionally well with a reverse-mounted Nikon 6& close-up lens on the front of it. This lens combo is specifically mentioned as being exceptional by Bjorn Rorslett, the Nikon lens expert, on his web site's lens review sections.
NIKON 100-300MM F 5.6 AIS MANUAL FOCUS LENS 62 - KEH Camera
AS he wrote:
Zoom Lenses For Nikon F Mount Telephoto
"The real surprise of the 100-300, however, comes when you put a close-up lens onto its front threads. I employed my standard Nikon 6T (reverse-mounted) and was
absolutely floored by the high quality close-ups produced by this combination. High image sharpness and contrast, perfectly flat field, and virtually no CA are features you associate with an expensive Micro-Nikkor, not a makeshift combination of a achromatic attachment and a consumer zoom lens. Food for some real thoughts"
I acquired a Nikon 6T and reversing ring for it myself...what he wrote is true. On 24 MP FX Nikon, the closeups are staggeringly good from the 100-300 zoom.