Magnesium, vitamin D, omega-3, and B vitamins all play important roles in overall health, and knowing which forms to look for can make a difference in how well your body absorbs and uses these essential nutrients.
Dr. Beth Bartlett shares some clinical pearls about magnesium and vitamin D, followed by omega-3 fatty acids and B vitamins. She discusses common signs that levels may be low, the forms she recommends, and why absorption matters when choosing supplements.
Magnesium: The Mineral Many People Are Missing
Up to about 80% of the population may be deficient in magnesium, making it one of the minerals people are most commonly deficient in.
Some symptoms of magnesium deficiency can include:
- Waking up around 3 a.m.
- Muscle cramps
- Headaches
- Anxiety
- Constipation
- Heart palpitations
- Low energy
The form of magnesium really matters. Magnesium oxide, which is typically found on drugstore shelves, has relatively low absorption. Dr. Bartlett recommends magnesium glycinate or magnesium bisglycinate, which absorbs well and is gentle on the digestive system.
“It’s great for sleep and anxiety,” she says.
For sleep and anxiety, Dr. Bartlett commonly recommends 400 to 600 milligrams, although she suggests starting at a lower dose and building up. Some people may take part of their dose with dinner and the remainder at bedtime. Dr. Bartlett takes about three capsules approximately 30 minutes before bed.
Choosing the Right Form of Magnesium
Different forms of magnesium may be useful for different purposes.
Magnesium glycinate or bisglycinate is well absorbed and gentle on the digestive system, making it a good option for sleep and anxiety.
Magnesium threonate crosses the blood-brain barrier and may be used for brain health and cognition.
Magnesium citrate has a more pronounced laxative effect and is available in powder form.
When considering a magnesium supplement, the form is therefore an important consideration—not simply the amount of magnesium listed on the bottle.
Vitamin D: Immunity, Mood, Bones, and Brain Health
Vitamin D deficiency can show up in several ways, including low immunity, low mood, fatigue, bone issues, and concerns related to brain health.
Dr. Bartlett recommends looking for vitamin D3 rather than D2. D3 is the form your body makes from exposure to sunlight and is also better absorbed.
She also recommends pairing vitamin D with vitamin K2 in the MK-7 form. Vitamin K helps transport calcium where the body needs it, including the bones and teeth.
Dr. Bartlett describes vitamin K as the “vehicle” used to transport calcium from vitamin D into the bones and teeth, rather than allowing calcium to accumulate where it isn’t wanted.
Why the Way You Take Vitamin D Matters
Vitamins A, D, E, and K are fat-soluble vitamins, meaning they need fat at a meal to be absorbed properly.
Dr. Bartlett notes that many people are prescribed larger amounts of vitamin D at one time, such as a weekly dose. However, she says some people may do better with smaller daily amounts rather than one large weekly dose because the body can only process so much vitamin D at one time.
She uses a liposomal vitamin D and K combination. According to Dr. Bartlett, the liposomal form is designed to bypass some of the digestive breakdown required with a traditional capsule and allow the nutrients to be absorbed more readily.
Vitamin D levels are also something she monitors personally. She says her level is around 47 and that she would like to reach at least 70. Even though she spends time outside, she takes about seven sprays of her vitamin D supplement each day.
Sun exposure can contribute to vitamin D production, but adequate exposure can be difficult to achieve. Dr. Bartlett points out that meaningful vitamin D exposure requires torso exposure for approximately 15 to 20 minutes a day—something she says she isn’t likely to do at this stage of her life.
Omega-3 Fatty Acids: Essential for the Body
In the second part of the series, Dr. Bartlett turns to omega-3 fatty acids and B vitamins.
Omega-3 fatty acids are essential fats, meaning the body cannot make them. They must come from food, supplements, or other dietary sources.
Low omega-3 levels can show up as:
- Dry skin
- Dry hair
- Poor memory and concentration
- Reduced brain function
- Low mood
- Stiff joints
When choosing a fish oil supplement, Dr. Bartlett recommends looking beyond the words “fish oil 1,000 milligrams.”
Look for EPA and DHA
The label should list EPA and DHA separately.
If a supplement simply lists 1,000 milligrams of fish oil, you’re relying on digestion and enzymes to break that fish oil down into its individual fatty acids. According to Dr. Bartlett, that conversion is not always efficient.
“So, make sure when you’re vetting your fish oils, make sure they list EPA, DHA separately,” she advises.
B Vitamins: Energy, Stress, and Mood
The B vitamins Dr. Bartlett focuses on include B12, B6, and folate (B9).
“These are your energy, stress, and mood vitamins,” she says.
B vitamins support the production of neurotransmitters, including serotonin, dopamine, and GABA. When levels are low, you may notice a decrease in resilience and mood.
Why B12 Deserves Special Attention
Vitamin B12 is particularly important to watch because it is found almost entirely in animal products. As a result, vegetarians and vegans are commonly at risk of having low B12 levels.
People taking proton pump inhibitors (PPIs), which are acid-blocking medications such as Prilosec and Prevacid, may also need to pay attention to B12. Long-term use of these medications can reduce the absorption of B12 from food.
When supplementing with B12, Dr. Bartlett recommends looking for the methylated form, methylcobalamin, rather than cyanocobalamin. Methylcobalamin is an active form of B12 and may be better absorbed.
Choosing Supplements: Form and Absorption Matter
Whether you’re considering magnesium, vitamin D, omega-3 fatty acids, or B vitamins, Dr. Bartlett emphasizes that the specific form of a supplement matters.
A label showing the nutrient’s name and total amount doesn’t necessarily tell the whole story. Absorption, the form of the nutrient, how it is taken, and individual nutritional needs can all affect how the body uses a supplement.