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Dr. Udai Jayakumar's two cents on Nutrition
Dr. Udai shares his perspectives to help you decipher truth from falsehood when it comes to the your health.
Dr. Udai shares his perspectives to help you decipher truth from falsehood when it comes to the your health.
Vitamin K1 is abundant in a variety of plant and animal foods so it generally not necessary to take supplements of K1. In contrast, Vitamin K2 is often lacking in the diets of vegans. While there is currently no established Recommended Daily Allowance for Vitamin K2, increasing evidence suggests it may offer various health benefits, as discussed in this post and this video by Dr. Sean Hashmi.
Vegans who do not regularly consume natto, a Japanese dish made from fermented soybeans, should consider taking a Vitamin K2 supplement or a multivitamin that includes it, such as Dr. Fuhrman's Daily. Among the subtypes of Vitamin K2, MK-7 is the one that is best absorbed by the gastrointestinal tract.
Zinc is an essential mineral that plays a key role in our immune systems, which is why it is often included in cold remedies such as Airborne. It also supports various important functions in the body such as cell division, DNA and protein synthesis, and wound healing. The recommended dietary allowance (RDA) for zinc is 11 mg for adult men and 8 mg for nonpregnant women. Per the NIH Fact Sheet on Zinc, vegetarians (especially vegans) are among the groups most likely to have inadequate zinc levels. Those at risk should consider checking their levels and/or taking a multivitamin with zinc.
Phytonutrients are not vitamins or minerals. They consist of thousands of compounds produced by plants including many antioxidants. Studies are emerging that phytonutrients have a much larger health promoting role than previously known. This may in part explain why eating more plants brings a multitude of health benefits including protecting from heart disease and cancer as noted by WebMD.
Vitamin D is important for maintaining bone health, as it is essential for the absorption of calcium from the gastrointestinal tract. Most individuals do not obtain sufficient vitamin D from food sources alone. Our skin produces vitamin D when exposed to sunlight, although various factors can influence the amount synthesized. A blood test to assess vitamin D levels can help determine the need for supplementation. Normal levels of 25-hydroxy vitamin D range from 50 to 125 nmol/L. The most effective supplement for increasing vitamin D levels is vitamin D3 (cholecalciferol), which is best absorbed when taken with meals or fatty foods. The recommended intake for adults is between 600 and 800 IU per day, while the maximum safe daily dose is 4000 IU.
The recommended dietary allowance (RDA) for calcium is 1000 to 1200 mg per day for adults. The specific amount can be found here and it varies by age and gender. Calcium absorption varies by individual factors (eg. vitamin D level) and across different foods. If following the RDA recommendations, there's no need to worry about all those factors as the RDA guidelines are generally sufficient for most people. This table and this table show the amount of calcium in many foods per serving. Be cautious of tables that display calcium content per calorie or per 100 grams. The complexities of this topic are thoroughly explained in this video and its accompanying blog post. It's important to note that blood tests for calcium are not reliable for guiding therapy, as most of an individual's calcium is not found in the bloodstream. If your bone density scan (DEXA) shows osteoporosis or osteopenia, it's especially important to ensure you are getting enough calcium. However, most people should not exceed 2500mg/day, as excessive intake can lead to problems such as kidney stones. If you are taking more than 500 or 600mg of calcium each day, it is advisable to space them out across meals. The body can effectively absorb only about 500 mg of calcium at a time.
Most Americans, whether vegan or omnivore, get enough iron. However, menstruating women may need iron supplements due to regular blood loss. Physicians can identify iron-deficiency anemia with routine lab tests and can recommend iron supplementation if necessary. Pregnant women have higher iron requirements, which is why iron is included in most prenatal vitamins.
Although non-heme iron from plant foods is not absorbed as efficiently as heme iron found in meats, the relatively high iron content in many plant foods compensates for this difference. It is important to note that the absorption of non-heme iron can be hindered when consumed alongside calcium-rich foods or calcium supplements.
A deficiency in vitamin B12 can lead to various health issues, including dementia. The Recommended Daily Allowance (RDA) for non-pregnant adults is 2.4 mcg. However, individuals who require supplements are generally advised to take much higher doses than the RDA to account for vitamin B12's low absorption rate. Regular multivitamins typically contain low amounts of B12, so vegans and people over the age of 65 should consider a multivitamin specifically designed for vegans or a dedicated vitamin B12 supplement that provides adequate amounts. A blood test can determine a person's B12 level and guide appropriate supplementation.
There is no established upper limit for vitamin B12 supplementation due to its low potential for toxicity and the body's ability to excrete excess amounts, as noted in the NIH Fact Sheet on vitamin B12. According to NutritionFacts.org, vegans should consider taking a daily multivitamin that contains at least 50 mcg of B12 or a dedicated cyanocobalamin supplement of at least 2000 mcg weekly. Both vegans and non-vegans over the age of 65 should consider supplementing with at least 1000 mcg of vitamin B12 each day, as absorption from the gastrointestinal tract decreases with aging. Additionally, individuals with an autoimmune disease called pernicious anemia may require periodic vitamin B12 injections.
We produce enough cholesterol to meet our body's needs. Outdated guidance suggested that the amount of cholesterol consumed is not important and to reduce saturated fat intake instead. However, the optimal amount of cholesterol in one's diet is actually zero.
Everyone should minimize their intake of saturated and trans fats, aiming for as close to zero as possible. If weight loss is a goal, it can also be helpful to reduce the consumption of unsaturated fats, as all fats are calorie-dense. Plant-based diets have been shown to lower the risk of cardiovascular disease, largely due to their lower saturated fat content. However, coconut and palm oils are exceptions and should be avoided.
Omega-3s are a type of polyunsaturated fat that the human body cannot produce on its own, so they must be obtained through diet or supplements to support heart and brain health and reduce the risk of various chronic diseases. There are three types of Omega-3s: ALA, DHA, and EPA. Regular consumption of certain types of fish such as salmon, tuna, and sea bass can provide sufficient Omega-3s. Vegans can obtain adequate ALA from sources like flax seeds, chia seeds, and walnuts, but the ability to convert ALA into DHA and EPA is often inadequate. Therefore, vegans should consider taking algae-based supplements that contain DHA and EPA or have their Omega-3 levels tested with a home finger-stick test called the Omega-3 index.
Refined carbohydrates undergo processing that removes the bran and germ from each grain. Common examples include white bread, pastries, white pasta, and many breakfast cereals. This processing strips these carbohydrates of valuable fiber, vitamins, and minerals, leading to their rapid absorption in the digestive tract. As a result, there is a quick and significant spike in blood sugar levels, which is reflected in a high glycemic index. While low-carb diets can aid in weight loss by eliminating all carbohydrates, a better strategy is to focus on eliminating only refined carbohydrates.
Good or complex carbs are an excellent source of vitamins and fiber. They also promote satiety, which can help prevent overeating. Unfortunately, finding a healthy whole wheat bread in the grocery store can be challenging. If the ingredient list includes any of the following terms: white, durum, semolina, bleached, unbleached, enriched, or ancient grains, consider it a processed carb. You might also consider learning to make whole wheat bread with a bread machine to ensure a regular, fresh supply.
The Recommended Daily Allowance (RDA) for protein is 0.8 grams per kg of body weight (0.36 grams per pound), but many experts like Simon Hill suggest at least 1.2 grams per kg (0.54 grams per pound). For individuals weighing between 130 and 165 pounds, this equates to approximately 70 to 90 grams of protein per day. 5-15% of individuals have chronic kidney disease, and many are unaware that they have this condition. It can be diagnosed with a routine blood test. The optimal protein intake for these individuals varies based on the severity of their disease and whether they are on dialysis. Therefore, it is important for them to seek guidance from a nutritionist or physician.
Essential amino acids are those that must be obtained through diet. A vegan can achieve sufficient protein intake and obtain all essential amino acids by consuming a variety of plant foods, but it does require some extra planning. For vegans to ensure they are getting enough protein, they should include plenty of legumes in their diets, such as beans, tofu, and dals. Legumes are easy to prepare in an Instant Pot, and many excellent recipes can be found in this book: Plant-Based Instant Pot Cookbook.
Fiber's lower calorie density helps you feel satisfied without over-eating. A small minority of Americans get the minimum daily recommended amount of fiber in their daily diets. All fiber is not the same. It's important to eat a variety of plant foods to get as many different types of fiber as you can. Dr. Bulsiewicz recommends taking a little of everything when you're at a salad bar. He is featured in many podcasts and he wrote the book, Fiber Fueled.
