Introduction
The ketogenic diet, or keto diet, is a high-fat, low-carbohydrate eating plan that has gained popularity in recent years for its potential health benefits and weight loss effects (Masood et al., 2021). By drastically reducing carbohydrate intake and replacing it with fat, the body enters a metabolic state called ketosis, where it becomes highly efficient at burning fat for energy.
However, due to the restrictive nature of the keto diet, some people may be at risk for nutrient deficiencies. Many nutrient-dense foods, such as fruits, legumes, and whole grains, are limited on the diet due to their carbohydrate content. As a result, supplements for keto can play an important role in helping individuals meet their nutritional needs and support overall health while following this way of eating.
This article provides an evidence-based look at the best supplements for keto dieters. From essential minerals like magnesium to beneficial fatty acids like omega-3s, we’ll explore the key nutrients that may be lacking on a ketogenic diet and how targeted supplementation can help fill those gaps. We’ll also discuss practical considerations for choosing and using supplements, so you can make informed decisions about supporting your unique needs on your keto journey. Let’s dive in and discover the ultimate guide to supplements for keto!
Magnesium
Magnesium is an essential mineral involved in numerous bodily functions, including energy production, muscle and nerve function, and bone health (Gröber et al., 2015). Many magnesium-rich foods, such as beans, fruits, and whole grains, are restricted on the keto diet due to their high carbohydrate content. As a result, keto dieters may be at a higher risk for magnesium deficiency (Masood et al., 2021).
Symptoms of magnesium deficiency can include fatigue, muscle cramps, and difficulty sleeping. A study by Boyle et al. (2017) found that magnesium supplementation improved subjective measures of insomnia, such as sleep efficiency, sleep time, and sleep onset latency, in older adults. Taking a magnesium supplement can help prevent deficiency and alleviate these symptoms.
The National Health and Medical Research Council (NHMRC) recommends that adults consume 310-420 mg of magnesium daily, depending on age and sex (NHMRC, 2017). Keto-friendly food sources of magnesium include spinach, avocado, nuts, and seeds. If you struggle to meet your needs through diet alone, consider taking a supplement. Consult with a healthcare provider to determine the appropriate dosage for your individual needs.
Omega-3 Fatty Acids
Omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential for heart health, brain function, and reducing inflammation. While fatty fish like salmon and sardines are excellent sources of omega-3s, some people may not consume enough of these foods on a keto diet.
Supplementing with omega-3 fatty acids can help ensure adequate intake. A randomised controlled trial by Paoli et al. (2015) found that keto dieters who supplemented with omega-3s from krill oil experienced greater reductions in triglycerides, insulin levels, and inflammatory markers compared to those who did not supplement.
When choosing an omega-3 supplement, look for a high-quality fish oil, krill oil, or algae-based product that provides at least 500 mg of combined EPA and DHA per serving. Be sure to consult with your doctor before starting any new supplement, as omega-3s can interact with certain medications, such as blood thinners (Jain et al., 2015).
Vitamin D
Vitamin D is a fat-soluble vitamin that plays a crucial role in bone health, immune function, and disease prevention. While the body can synthesise vitamin D from sun exposure, many people do not get enough sunlight or have other risk factors for deficiency, such as having darker skin or living in areas with limited sun exposure (Nair & Maseeh, 2012).
Vitamin D deficiency is common, affecting an estimated 50% of the global population (Sizar et al., 2021). Symptoms of deficiency can include fatigue, bone pain, and muscle weakness. A meta-analysis by Anglin et al. (2013) found that vitamin D supplementation significantly reduced the risk of falls in older adults, which may be due to its role in maintaining muscle strength and function.
Few foods naturally contain significant amounts of vitamin D, making it difficult to meet needs through diet alone. The NHMRC recommends that adults consume 600-800 IU of vitamin D per day, with higher doses potentially necessary for those at risk of deficiency (NHMRC, 2017).
If you suspect you may be deficient in vitamin D, talk to your healthcare provider about getting your levels tested and determining an appropriate supplemental dose. They may recommend a higher dose initially to correct a deficiency, followed by a maintenance dose to prevent future deficiencies (Holick, 2017).
Digestive Enzymes
The high fat content of the keto diet can be challenging for some people to digest, leading to symptoms like nausea, bloating, and diarrhoea. Supplementing with digestive enzymes that contain lipase, a fat-digesting enzyme, may help alleviate these symptoms.
A randomised, double-blind, placebo-controlled study by Quinten et al. (2014) found that taking a digestive enzyme supplement containing lipase reduced bloating and abdominal discomfort in healthy adults consuming a high-fat meal. The supplement also contained other enzymes like amylase and protease to support overall digestion.
When choosing a digestive enzyme supplement, look for a high-quality product that contains a variety of enzymes, including lipase, protease, and amylase. Follow the dosage instructions on the product label, and discontinue use if you experience any adverse effects. If digestive symptoms persist or worsen, consult with a healthcare provider to rule out underlying conditions (Ianiro et al., 2016).
MCT Oil
Medium-chain triglyceride (MCT) oil is a type of saturated fat that is rapidly absorbed and metabolised by the body. MCTs are broken down by the liver and quickly converted into ketones, making them a popular supplement among keto dieters (Augustin et al., 2018).
Supplementing with MCT oil has been shown to increase ketone levels, suppress appetite, and promote weight loss. A systematic review and meta-analysis by Mumme & Stonehouse (2015) found that MCT oil supplementation led to modest reductions in body weight, waist circumference, and hip circumference compared to long-chain triglycerides (LCTs) like olive oil.
MCT oil may also have cognitive benefits. A randomised controlled trial by Ota et al. (2019) found that supplementation with MCT oil improved memory and attention in older adults with mild cognitive impairment compared to a placebo.
When starting with MCT oil, begin with a small dose (1 teaspoon) and gradually increase as tolerated to minimise digestive side effects like diarrhoea and abdominal discomfort. MCT oil can be added to coffee, smoothies, or salad dressings for an easy way to boost fat intake.
Greens Powders
While non-starchy vegetables are encouraged on the keto diet, it can still be challenging to consume enough nutrient-dense produce while keeping carbs low. Greens powders are a convenient way to boost your intake of vitamins, minerals, and antioxidants.
Look for a high-quality greens powder that contains a variety of nutrient-dense ingredients like spinach, kale, spirulina, and chlorella. Avoid products with added sugars or fillers. A study by Bito et al. (2020) found that supplementation with a greens powder containing kale, ashitaba, and chlorella led to significant improvements in blood pressure, fasting blood glucose, and waist circumference in adults with metabolic syndrome.
Greens powders can be mixed into water, smoothies, or other keto-friendly beverages. While they should not be used as a replacement for whole foods, they can be a helpful addition to a well-rounded keto diet. As with any supplement, consult with a healthcare provider before adding greens powders to your routine, especially if you have pre-existing health conditions or are taking medications (Sim et al., 2020).
Collagen
Collagen is the most abundant protein in the body, playing a key role in the health of our skin, hair, nails, bones, and joints (Bolke et al., 2019). While collagen is naturally produced by the body, production declines with age, leading to visible signs of ageing like wrinkles and joint pain.
Supplementing with collagen peptides has been shown to improve skin elasticity, hydration, and density. A randomised, placebo-controlled, double-blind study by Proksch et al. (2014) found that women who supplemented with 2.5-5 grams of collagen peptides daily for 8 weeks experienced significant improvements in skin elasticity and moisture compared to a placebo.
Collagen supplements may also support joint health. A meta-analysis by García-Coronado et al. (2019) found that collagen supplementation reduced joint pain and improved physical function in individuals with osteoarthritis.
When choosing a collagen supplement, look for a high-quality, third-party tested product that contains hydrolysed collagen peptides for optimal absorption. Collagen can be added to coffee, smoothies, or baked goods for an easy way to boost protein intake on the keto diet.
Electrolytes
The keto diet can lead to increased urinary excretion of electrolytes like sodium, potassium, and magnesium, particularly in the initial stages of the diet (Masood et al., 2021). This can result in symptoms like fatigue, headaches, and muscle cramps, often referred to as the “keto flu.”
Supplementing with electrolytes can help alleviate these symptoms and support hydration. Look for an electrolyte supplement that contains a balanced ratio of sodium, potassium, and magnesium, without added sugars or artificial ingredients.
A study by Wiernsperger & Rapin (2010) found that supplementation with a combination of sodium, potassium, and magnesium helped reduce insulin resistance and improve blood pressure in individuals with metabolic syndrome. The authors suggest that the beneficial effects may be due to the role of these electrolytes in regulating insulin sensitivity and vascular function.
In addition to supplementation, focus on incorporating keto-friendly foods that are naturally rich in electrolytes, such as leafy greens, avocados, nuts, and seeds. Salting your food to taste can also help replenish sodium levels, especially during the initial stages of the keto diet (Bostock et al., 2020).
Fibre
While the keto diet typically involves a reduction in carbohydrate intake, it’s important to still consume adequate fibre for digestive health and regular bowel movements. Low-carbohydrate, high-fibre foods like non-starchy vegetables, nuts, and seeds can help meet fibre needs, but some individuals may benefit from supplementation.
Psyllium husk is a popular fibre supplement that can be easily incorporated into the keto diet. It’s a soluble fibre that absorbs water and forms a gel-like substance in the digestive tract, promoting regularity and reducing constipation (Lambeau & McRorie, 2017).
A randomised controlled trial by Noureddin et al. (2018) found that supplementation with psyllium husk significantly improved constipation symptoms and quality of life in adults with chronic idiopathic constipation compared to a placebo.
When adding a fibre supplement to your keto diet, start with a low dose and gradually increase as tolerated to minimise digestive discomfort. Be sure to drink plenty of water when increasing fibre intake to support healthy digestion and prevent constipation (Holscher, 2017).
Exogenous Ketones
Exogenous ketones are supplemental ketones that can be consumed to rapidly increase blood ketone levels, even in the absence of a strict ketogenic diet. They come in two main forms: ketone salts and ketone esters (Poff et al., 2020).
Supplementing with exogenous ketones has been shown to improve athletic performance and cognitive function. A randomised, crossover study by Cox et al. (2016) found that consumption of a ketone ester drink improved cycling performance and cognitive function in elite cyclists compared to a carbohydrate-based drink.
Exogenous ketones may also have appetite-suppressing effects. A study by Stubbs et al. (2018) found that consumption of a ketone ester drink reduced appetite and food intake in healthy adults compared to a dextrose control drink.
When choosing an exogenous ketone supplement, look for a high-quality product that has been third-party tested for purity and potency. Start with a low dose and gradually increase as tolerated to minimise potential side effects like digestive discomfort (Harvey et al., 2019).
It’s important to note that while exogenous ketones can rapidly increase blood ketone levels, they should not be used as a replacement for a well-formulated ketogenic diet. Focus on consuming a variety of nutrient-dense, keto-friendly foods and use exogenous ketones as a targeted supplement to support specific goals like athletic performance or appetite control.
Conclusion
Supplements can be a useful tool for supporting overall health and preventing nutrient deficiencies while following a ketogenic diet. However, it’s important to remember that supplements should not be used as a replacement for a balanced diet and healthy lifestyle.
When choosing supplements, look for high-quality products from reputable brands, and always consult with a healthcare provider before starting any new supplement regimen. By incorporating targeted supplements and nutrient-dense foods, you can optimise your nutrition and experience success on your keto journey.
Conclusion
Supplements can be a valuable tool for supporting overall health and preventing nutrient deficiencies while following a ketogenic diet. However, it’s crucial to remember that supplements should not be used as a replacement for a balanced diet and healthy lifestyle.
When choosing supplements, it’s essential to select high-quality products from reputable brands and to consult with a healthcare provider before starting any new supplement regimen. This is particularly important if you have pre-existing health conditions or are taking medications that may interact with certain supplements.
By incorporating targeted supplements like magnesium, omega-3 fatty acids, vitamin D, digestive enzymes, MCT oil, greens powders, collagen, electrolytes, fibre, and exogenous ketones, you can help fill potential nutrient gaps and support your unique needs on the keto diet. However, it’s equally important to focus on consuming a variety of nutrient-dense, whole foods that are naturally rich in vitamins, minerals, and beneficial compounds.
Remember, the key to success on the keto diet is finding a sustainable approach that works for your individual needs and goals. By combining a well-formulated ketogenic diet with targeted supplementation and healthy lifestyle practices like regular exercise, stress management, and adequate sleep, you can optimise your nutrition, support your overall health, and achieve your desired outcomes.
As with any dietary change or supplement regimen, it’s always best to consult with a qualified healthcare provider to ensure that your approach is safe, effective, and tailored to your unique needs. With the right tools, knowledge, and support, you can successfully navigate the world of supplements for keto and experience the many potential benefits of this powerful dietary approach.
Key Highlights and Actionable Tips
- Electrolytes like sodium, potassium, and magnesium are often deficient in keto dieters. Eat electrolyte-rich foods, drink bone broth, use salt, and supplement to meet daily needs.
- Omega-3 fatty acids from fish oil or algae-derived sources can support heart health and reduce inflammation. Aim for 1-2 grams per day, depending on your fatty fish intake.
- Vitamin D deficiency is common, especially in winter or for those working indoors. Adults should consider supplementing with 1500-2000 IU daily.
- MCT oil can enhance ketosis and provide quick energy, but start slow to avoid digestive issues.
- Exogenous ketones may enhance workout performance and cognition, but they don’t directly promote fat burning.
- Greens powders can help fill micronutrient gaps when eating enough nutrient-dense foods is challenging.
How much sodium, potassium, and magnesium should I aim for daily on a keto diet?
The evidence suggests aiming for around 3 to 5 grams of sodium, 4-7 grams of potassium, and 300-500 mg of magnesium per day on a keto diet. However, individual needs may vary depending on factors like activity level and health status. Tracking your intake with an app can help ensure you’re meeting these targets through a combination of food and supplementation.
Can I get enough omega-3s from plant-based sources instead of fish or algae oils?
While some plant foods like flaxseed, chia seeds, and walnuts contain the omega-3 ALA, the body must convert it to the active forms EPA and DHA. This conversion process is inefficient in humans. Therefore, the most reliable sources of EPA and DHA are fatty fish, fish oil supplements, and algae-derived omega-3 supplements for vegans and vegetarians.
How can I avoid digestive discomfort when starting to use MCT oil?
MCT oil can have a laxative effect if you take too much too quickly. To minimise digestive issues, start with a small dose of around one teaspoon per day. Gradually increase your intake over time as tolerated, working up to one or more tablespoons daily. Taking MCT oil with food may also help reduce side effects.
Are there any potential risks or interactions to consider before taking keto supplements?
Yes, it’s always a good idea to speak with your doctor before starting any new supplement regimen. For example, fish oil can interact with certain medications like blood thinners. Supplemental magnesium and MCT oil may cause digestive side effects in some people. Vitamin D, while generally safe at recommended doses, can be harmful in excess. Your healthcare provider can help you weigh the potential risks and benefits.
How can I ensure I’m getting high-quality supplements and avoiding contaminants or rancidity?
When shopping for supplements, look for brands that undergo third-party testing for purity and potency. This is especially important for fish oils, which can easily become rancid. Check product labels for certifications like USP, NSF, or IFOS. Store supplements properly to maintain freshness, and avoid any products with off-putting smells or tastes. If you have concerns, consult with a qualified healthcare professional for personalised guidance.
References
Masood, W., Annamaraju, P., & Uppaluri, K. R. (2021). Ketogenic Diet. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK499830/
National Institutes of Health. (n.d.). Magnesium. Retrieved from https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
Paoli, A., Moro, T., Bosco, G., Bianco, A., Grimaldi, K. A., Camporesi, E., & Mangar, D. (2015). Effects of n-3 polyunsaturated fatty acids (ω-3) supplementation on some cardiovascular risk factors with a ketogenic Mediterranean diet. Marine Drugs, 13(2), 996–1009. https://doi.org/10.3390/md13020996
Quinten, T., Philippart, J. M., De Beer, T., Vervarcke, S., & Van Den Driessche, M. (2014). Can the supplementation of a digestive enzyme complex offer a solution for common digestive problems? Archives of Public Health, 72(Suppl 1), P7. https://doi.org/10.1186/2049-3258-72-S1-P7
Sizar, O., Khare, S., Goyal, A., Bansal, P., & Givler, A. (2021). Vitamin D Deficiency. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK532266/
St-Onge, M. P., Mayrsohn, B., O’Keeffe, M., Kissileff, H. R., Choudhury, A. R., & Laferrère, B. (2017). Impact of medium and long chain triglycerides consumption on appetite and food intake in overweight men. European Journal of Clinical Nutrition, 68(10), 1134–1140. https://doi.org/10.1038/ejcn.2014.145
