Greater vitamin K1 intake associated with decreased cataract risk

This hit my inbox earlier this month and I am forwarding it on. It should be of interest to anyone over the age of 55.

This issue of Life Extension Update examines a report appearing in the American Medical Association journal JAMA Ophthalmology which documents a lower risk of developing cataracts among older individuals who had a higher daily intake of vitamin K1.

Tuesday, June 6, 2017

“Inflammation and oxidation could underlie the cataract formation,” note Maria L. Camacho-Barcia, RD, MSc, and colleagues in their introductory remarks. “Because vitamin K has anti-inflammatory and antioxidant properties and is related to glucose and insulin metabolism, we hypothesize that dietary vitamin K1 intake would be associated with a decreased risk of cataracts among an elderly Mediterranean population.”

The study included data from 5,860 men and women whose age averaged 66.3 years upon enrollment in the Prevencion con Dieta Mediterranea (PREDIMED) study, a randomized cardiovascular prevention trial involving participants at high cardiovascular risk. Questionnaires completed at enrollment and yearly thereafter provided information on the subjects’ daily intake of vitamin K1 and other factors.

During a median 5.6 years of follow-up, 768 new cataracts were documented. Among those whose average daily intake of vitamin was among the highest one-third of subjects, at a median of 496.7 micrograms, there was a 29% lower adjusted risk of undergoing cataract surgery in comparison with subjects whose intake was among the lowest third, at 249.4 micrograms per day.

The authors observe that the eyes’ lens proteins are subject to changes during aging accompanied by a compromised antioxidant system. Chronically elevated levels of blood glucose and inflammation, which can also occur with aging, additionally contribute to cataract formation. In agreement with epidemiologic studies that have revealed an association between a lower risk of cataracts and diets rich in antioxidant and anti-inflammatory nutrients, the current study’s results could be explained in part by vitamin K’s antioxidant and anti-inflammatory properties, as well as the vitamin’s association with lower glucose levels.

“The results of this study suggest a protective role of high vitamin K1 dietary intake on cataract incidence in a senior Mediterranean population even after adjusting by other potential confounders,” Camacho-Barcia and her associates conclude.

In case you aren’t familiar vitamin K1 (Phylloquinone) it is  one of our major blood clotting factors. It is found in green leafy vegetables and  also produced by the health bacterial in our digestive tract.  I’ve included a food chart from the Linus Pauling Institute, Oregon State University, ( If you would like to read more on vitamin K1 this is an excellent source to start with.


Table 2. Some Food Sources of Phylloquinone
Food Serving Phylloquinone (μg)
Kale, raw 1 cup (chopped) 472
Swiss chard, raw 1 cup 299
Parsley, raw ¼ cup 246
Broccoli, cooked 1 cup (chopped) 220
Spinach, raw 1 cup 145
Watercress, raw 1 cup (chopped) 85
Leaf lettuce (green), raw 1 cup (shredded) 46
Soybean oil 1 Tablespoon 25
Canola oil 1 Tablespoon 10
Olive oil 1 Tablespoon 8
Cottonseed oil 1 Tablespoon 3

I also wanted to bring to your attention that blood thinner medication interfere with K1 levels in the body. Also, antibiotic therapy kills the healthy bacteria along with the unhealthy bacteria and can reduce the production and absorption of K1 in our digestion tract thus reducing our levels of K1. For your convenience I’ve included a link to the Nation Institutes of Health if you want to read more on drug interactions.


Interactions with Medications

Vitamin K interacts with a few medications. In addition, certain medications can have an adverse effect on vitamin K levels. Some examples are provided below. Individuals taking these and other medications on a regular basis should discuss their vitamin K status with their health care providers.

Warfarin (Coumadin®) and similar anticoagulants

Vitamin K can have a serious and potentially dangerous interaction with anticoagulants such as warfarin (Coumadin®), as well as phenprocoumon, acenocoumarol, and tioclomarol, which are commonly used in some European countries [7,8]. These drugs antagonize the activity of vitamin K, leading to the depletion of vitamin K-dependent clotting factors. People taking warfarin and similar anticoagulants need to maintain a consistent intake of vitamin K from food and supplements because sudden changes in vitamin K intakes can increase or decrease the anticoagulant effect [44]. Additional information on the interaction between warfarin and vitamin K is available from the National Institutes of Health Clinical Centerexternal link disclaimer.


Antibiotics can destroy vitamin K-producing bacteria in the gut, potentially decreasing vitamin K status. This effect might be more pronounced with cephalosporin antibiotics, such as cefoperazone (Cefobid®), because these antibiotics might also inhibit the action of vitamin K in the body [6,45]. Vitamin K supplements are usually not needed unless antibiotic use is prolonged (beyond several weeks) and accompanied by poor vitamin K intake [45].

I hope you find this information helpful and will adjust your diet accordingly.
“An Ounce of Prevention IS Worth a Pound of Cure”  
is just as true today as it was when Benjamin Franklin wrote it.

Yours in Health,
Dr. Eckert