Calling vitamin D a vitamin is medical gaslighting. It's a steroid hormone that controls over 1,000 genes in your body—including the ones that regulate testosterone, estrogen, and your ability to not feel like death.

70-80% of people are deficient. And no, your multivitamin's 1,000 IU isn't fixing it.

For men: Your testosterone is directly tied to vitamin D levels. Guys with levels above 30 ng/ml have significantly higher T than those below. But here's the kicker—30 is still deficient. You need 40-60 ng/ml for optimal testosterone production.

For women: Vitamin D regulates estrogen and progesterone balance. Deficiency means worse PMS, mood swings, and hormonal chaos. Women with optimal D levels show 50% fewer hormone-related symptoms.

For everyone: This controls whether you can make serotonin. Literally. It activates the enzyme (tryptophan hydroxylase 2) that converts tryptophan into serotonin. No D = no happy chemicals = depression.

If you have darker skin, you need six times longer sun exposure to make the same vitamin D as someone pale. If you're Black or Brown and live anywhere north of Atlanta, you're almost guaranteed deficient.

Over 50? Your skin basically forgot how to make vitamin D. You could lay in the sun all day and still be deficient.

Dose: 5,000-10,000 IU daily (not the joke 1,000 IU your doctor suggests)

Target: 40-60 ng/ml on blood tests

Reality: Every 1,000 IU raises levels by only 5 ng/ml. If you're at 20 ng/ml (most people), you need 8,000 IU daily to hit optimal.

Take with: Fat (breakfast works). Add 100-200mcg K2 to prevent calcium issues.

Test: Every 3 months until optimal (if possible)

For stressed men: Magnesium regulates cortisol. High cortisol crushes testosterone. Every night of bad sleep is lowering your T levels. Fix the magnesium, fix the sleep, restore the testosterone.

For exhausted women: Magnesium is required to make progesterone—your calming, sleep-promoting hormone. Without it, you're anxious, irritable, and exhausted but wired.

That afternoon death feeling? Magnesium is required to make ATP—literal cellular energy. Without it, your cells can't produce energy efficiently. You're running on 60% battery all day.

Signs you're deficient:

Muscle cramps or eye twitches

Chocolate cravings (your body wants magnesium)

Anxiety that coffee makes worse

Feeling tired but unable to sleep

For sleep: Magnesium threonate (145mg) or glycinate (400mg)—only forms that cross the blood-brain barrier

For constipation: Citrate (but won't help sleep)

When: 30-60 minutes before bed

Your brain is 60% fat. The quality of that fat determines whether you're sharp or shuffling through life in a fog.

Americans average 5% omega-3 index. Japan averages 11%. Guess who has lower depression, better hormones, and doesn't age like milk?

Studies show 1,000mg EPA (the anti-inflammatory omega-3) works as well as Prozac for depression. Without the sexual side effects. Without the emotional numbness. Without the weight gain.

How? Depression is often just inflammation in disguise. EPA crushes inflammation, allowing your brain to actually make serotonin. Inflammation literally blocks neurotransmitter production.

For men: Omega-3s reduce inflammation that tanks testosterone. Better blood flow everywhere (yes, there too). Higher omega-3 = better testosterone optimization.

For women: Reduces inflammatory PMS symptoms by up to 40%. Stabilizes mood throughout your cycle. Makes periods less hellish.

DHA (the other omega-3) literally builds your brain structure. Low DHA means:

Your neurons are made of DHA. Trying to think without DHA is like trying to build a house without wood.

Therapeutic dose: 2-3g EPA for mood/inflammation, minimum 300mg DHA for brain

Quality matters:

Timing: With your fattiest meal

Testing: Omega-3 index every 6 months (target: 8% minimum)

Food alternative: Wild salmon 3x/week. But let's be real—you're not doing that.