From the journal Nutrition:
A 12-week ketogenic diet was shown to have many beneficial effects in healthy obese adults, but it is not clear if the supply of micronutrients is adequate.
In 35 adult individuals with BMI above 30, the intakes of minerals and their serum levels were analyzed at baseline and at weeks 4 and 12 of the ketogenic diet intervention. The intake of vitamins and serum antioxidative potential were also investigated.
Throughout the diet the intakes of magnesium, calcium, iron, phosphorus and potassium were below recommended values, but their serum levels always remained within the reference range. Nevertheless, the level of calcium decreased significantly (from 2.52 ± 0.10 mmol/L at baseline to 2.36 ± 0.07 mmol/L at week 12, P < 0.001) which could be due to the omission of legumes and reduced dairy intake or due to the high fat intake alone. The levels of phosphate increased concomitantly. Calcium serum levels were negatively associated with ω-6 but not with ω-3 unsaturated fatty acid intake. The intakes of water-soluble vitamins were also too low. However, the antioxidative potential of serum did not change during intervention.
Careful choice of foods which would provide the necessary micronutrients is of utmost importance when consuming ketogenic diet. In the 12 weeks the decreased intakes did not reflect in serum values, but special attention to calcium should be advised if such diet is recommended through longer periods.
Steve Parker, M.D.
A ketogenic diet — including a “careful choice of foods which would provide the necessary micronutrients” — is one of two options in The Advanced Mediterranean Diet.