Vitamin D3-K2 Emulsion by Nutra BioGenesis

This emulsion fits adults whose Vitamin D (25-hydroxy) has tested low and who want a daily repletion dose as a liquid, with vitamin K2 alongside. People who often run low include those with little sun exposure, darker skin at northern latitudes, higher body weight or fat-absorption problems. At 125 mcg of vitamin D3 per serving this is a high dose. It is for correcting a measured shortfall with your clinician, not for routine use when your level is already in range.

Vitamin D3 (cholecalciferol) is the form skin makes from sunlight. The liver and kidneys convert it into the hormone that raises calcium absorption from the gut and helps keep parathyroid hormone in check. Vitamin K2, here as menatetrenone (also called MK-4), activates proteins such as osteocalcin that bind calcium into bone. The two are often paired for that reason, though evidence that adding K2 improves outcomes over vitamin D alone is mixed. Both are emulsified in water and organic olive oil, and the label marks the product vegan, gluten free and GMO free.

One serving is 5 drops (1/4 mL) and provides 125 mcg of vitamin D3 and 50 mcg of vitamin K2. The label directs 5 drops once daily, or as directed by your healthcare practitioner. Shake the bottle, count the drops onto a spoon, and take them with a meal that contains some fat. Count carefully: the bottle holds 120 servings, so a full squeeze of the dropper can deliver several days' worth at once. Refrigerate after opening.

Vitamin K works against warfarin and other vitamin K antagonist anticoagulants, so do not start or stop this product without your prescriber if you take one. High-dose vitamin D raises the risk of high calcium in people taking thiazide diuretics and in those with sarcoidosis, primary hyperparathyroidism, kidney disease or a history of kidney stones. Orlistat and bile acid sequestrants reduce absorption. The label asks you to keep your practitioner informed, especially if pregnant or nursing.

Vitamin D (25-hydroxy) usually rises over 8–12 weeks, so retest at about three months, with Calcium, and step down once you are in range: 125 mcg a day is above the 100 mcg set as the adult upper limit for unsupervised use. Signs of too much are those of high calcium, such as thirst, frequent urination, nausea and constipation. A softgel does the same job if you would prefer not to count drops.