Vitamin K2: The Cofactor Most People Miss
The ketogenic diet requires attention to micronutrients often overlooked in standard diets. Vitamin K2, a lesser-known cofactor, plays critical roles in calcium metabolism and cardiovascular health. Found primarily in animal fats and fermented foods, this nutrient is frequently missed even by those following careful keto protocols.
What Vitamin K2 Does in the Body
Vitamin K2 activates proteins that regulate where calcium deposits in the body. Unlike vitamin K1 (found in leafy greens), K2 directs calcium to bones and teeth while preventing arterial calcification. A 2017 review in Nutrients found K2 supplementation improved arterial stiffness in healthy postmenopausal women. Grass-fed dairy from UK supermarkets like Waitrose contains natural K2, with 100g of aged Gouda providing about 75μg for £2.20.
Why Keto Diets Need Special Attention to K2
Low-carb diets naturally reduce intake of fortified grains, a common K2 source in standard diets. Research in the Journal of Nutrition shows K2 works synergistically with vitamin D3, another nutrient of concern in UK winters. the importance of vitamin D on keto becomes particularly relevant between October and March when sunlight exposure decreases.
Best Food Sources in the UK
UK shoppers can find K2 in:
- Grass-fed butter (£1.80 for 250g at Sainsbury’s)
- Natto (fermented soybeans, available in Asian supermarkets)
- Egg yolks from pasture-raised chickens
- Hard cheeses like Emmental and Edam
Fermentation increases K2 content, making traditional cheeses a practical choice. The NHS recommends 1μg of K2 per kg of body weight daily, though optimal amounts for keto adaptation remain under study.
Supplementation Considerations
For those not consuming daily K2-rich foods, supplements provide MK-7 (from natto) or MK-4 (animal-derived). A 2013 meta-analysis in Osteoporosis International found MK-7 more bioavailable with longer half-life. Typical doses range from 100-200μg daily, with costs around £15 for a three-month supply at Boots.
What This Means in Practice
Pairing K2 intake with vitamin D3 enhances calcium metabolism – crucial for maintaining bone density during weight loss. Autumn and winter months warrant particular attention, as seen in a Cambridge University study tracking nutrient status seasonally. For meal planning, adding 30g of aged cheese or a tablespoon of grass-fed butter covers approximately half the daily K2 needs.
Frequently Asked Questions
Is vitamin K2 the same as the K1 in spinach? No. While both are vitamin K forms, K1 primarily supports blood clotting whereas K2 regulates calcium distribution. The body converts some K1 to K2, but not efficiently enough to meet requirements.
Can you get enough K2 from diet alone? Possible but challenging. Regular consumption of grass-fed dairy, organ meats, and fermented foods can provide adequate K2, but many find supplementation more practical.
Does cooking destroy vitamin K2? K2 is heat-stable, so cooking doesn’t significantly degrade it. However, opting for raw or minimally processed sources ensures maximum nutrient retention.
The Bottom Line
Vitamin K2 serves as a critical but often neglected component of ketogenic nutrition, supporting both cardiovascular and skeletal health. While UK supermarkets provide accessible food sources, supplementation may benefit those with limited access to grass-fed dairy or fermented foods. Tracking intake becomes simpler with keto nutrient tracking, and for those who prefer automated calculations, the Keto Dieting app handles the maths on Google Play and the App Store.
References
- Kosinski C, Jornayvaz FR (2017). Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients. https://doi.org/10.3390/nu9050517
- Paoli A, Rubini A, Volek JS, Grimaldi KA (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition. https://doi.org/10.1038/ejcn.2013.116
