A little more about supplements: If this can help anybody....

First, regarding calcium citrate mentioned in the article, every source I have read about it states it can be absorbed on an empty stomach, unlike the calcium carbonate form.

The following is a matter of not only getting calcium absorbed in the gut with vitamin D3, but vitamin K2's role of pulling calcium out of the blood stream and into the bone.

Some of you may know about vitamin K2 being important. I have done some research about how it's involved in bone building. The simple explanation is that vitamin K2 directs calcium out of the bloodstream and to the bone.

A very good article about vitamin K2 - https://www.healthline.com/nutrition/vitamin-k2#bone-health

And from another article, quote, "Vitamin D & vitamin K2 are complimentary vitamins. While Vitamin D is necessary for absorbing calcium from food in the intestines, Vitamin K2 does two functions that help direct the calcium to the correct spot:
1) by activating Osteocalcin, a protein that promotes accumulation of calcium in bones and teeth, and
2) by decreasing accumulation of calcium in soft tissues, such as kidneys and blood vessels

Vitamin K2 is found in beef liver, egg yolk, soft cheese and fermented foods."
Source: https://www.hyperparathyroidmd.com/hyperparathyroidism-vitamin-d/

I get K2 from supplements and natto too. Natto is a fermented soybean product found in some Asian food stores.

I freeze my natto since I use only 2 teaspoons daily and don't want it to spoil. I also take the brand Nature Made D3 with Vitamin K2 daily and aim for 100-300 micrograms of Vitamin K2 daily. The supplement has 100mcg.

I take my vitamin D3, calcium, zinc, magnesium combo pill, four pills dosed throughout the day. I take the first pill with the vitamin K2 supplement and the third pill with 2 teaspoons of natto.