Persona Nutrition uses an in-depth questionnaire that covers nutrition, lifestyle, physical activity, prescription medications, sleep, dietary preferences and more. This information allows Persona to formulate vitamin packs with all the nutrients you need. 

You'll receive packs of vitamins with instructions to take them at specific times of day, because the bioavailability of any particular nutrient depends on what else is in your body at the moment. 

For example, it's best to take water-soluble vitamins such as vitamin B12 soon after waking up because an empty stomach can help you absorb them. Fat-soluble vitamins such as vitamins K and E, on the other hand, are best taken with a meal because your body won't absorb the vitamins without the help of dietary fat. Some vitamins also need to be taken in tandem to ensure absorption (like vitamin D and calcium).

Persona Nutrition ships orders every 28 days. Your vitamins arrive in convenient daily packets designed to be taken in the morning, afternoon and night, depending on the contents of your subscription. Persona offers nearly 100 products, and the cost of your box will vary based on which products you add to your subscription. The vitamin brand offers personalized packs for as little as $30 a month.

Hum Nutrition started with one man's personal struggles with skin breakouts and blemishes. Founder Walter Faulstroh found that prescription medications only worked temporarily for him, and topical treatments left his skin -- and his confidence -- scarred.

Hum got its start creating vitamin supplements intended to contribute to healthy, clear skin, but the brand has since expanded to include a comprehensive offering of products for hair and nails, digestion, immunity, energy, bones and joints, sleep, stress and metabolism.

A 3-minute quiz unlocks your wellness profile and a free consultation with a registered dietitian. Your Hum profile reveals what the company says would be your most effective combo of nutrients, vitamins and minerals and your RD counsels you further. You can choose to stick with your recommendations or shop around for other products.

You'll receive your Hum subscription box every 30 days, whether you sign up for a month-to-month subscription or buy a Commit and Save plan for three, six or 12 months.

The price of your subscription box will vary based on which vitamins and nutrients you choose. Hum's products range from $10 to $60. Hum ships worldwide and shipping is free for all orders over $50.

Baze uses blood monitoring as the main driver of supplement selections. When you sign up for Baze, you'll receive a blood nutrient testing kit in the mail. It works like a blood sugar monitor: You stick it in your upper arm and it measures the nutrient content of your blood. You only have to wear it for 5 minutes, and then you ship it back to Baze. 

Then, based on your blood sample and lifestyle questionnaire, Baze's staff dietitians develop your vitamin and supplement formula. They'll also send a detailed nutrient report to you through your account, which you can see in the Baze app.

You can reassess your nutrient levels whenever you want, and your dietitians will modify your vitamin packs based on your new results.

I love that Baze has created a food guide that educates you on how nutritional supplements and food go hand-in-hand. What and when you eat affects how your body processes and absorbs the nutrients from your supplements -- you can optimize the process by understanding how this works. 

Baze vitamin packs ship monthly for free.

Vous Vitamin was founded by two doctors who kept seeing patients come in with similar symptoms -- fatigue, lack of focus, thinning hair, skin problems and so on -- and kept tracing these issues back to nutrient deficiencies or poor dietary habits. 

You'll start out with a questionnaire that asks all the basics, plus questions about how you sleep, eat and move. You'll also provide information about any health conditions you have or medications you take.

I like Vous Vitamin because you only have to take one pill. Instead of vitamin packs with two to six pills, Vous Vitamin packs all of your recommended nutrients into one caplet that you take twice daily (you can take one pill in the morning and one at night, or take both at the same time). 

You can also purchase individual "situational supplements," such as Recovery Act (a hangover cure) and Power Up (an energy boost), for when you need a little extra something. 

Vous Vitamins ship every three months or every six months, and shipping is free. You can save more money each month if you choose the six-month subscription.

Thesis is unique in that it focuses on solving specific symptoms with supplements, rather than estimating nutrient needs based on a lifestyle quiz. You still take a quiz -- and there's still an algorithm to determine dosage of ingredients -- but your recommendations are based on your answers to questions like, "How long is your average attention span?"

Thesis's main focus is brain health and cognitive functioning, rather than the whole-body approach that other vitamin subscription services take. Thesis's approach also narrows the supplement span down to a specific category: nootropics. 

Nootropics, according to Thesis, are "nutrient compounds shown to enhance mental performance in areas such as motivation, creativity, mood, memory, focus, and cognitive processing." 

Thesis packets ship once a month, and shipping is free within the US. You can opt for a one-time purchase, but you'll pay $40 more for it. 

Rootine boasts one of the most robust data-collection methods out of all the vitamin subscription services. Like the others, it begins with a quiz about your lifestyle, and the company says it uses that information, plus your age and body size, to calculate your exact needs for micronutrients and minerals and a well-balanced diet. 

To customize further, you can order a DNA test with your first purchase or input data you already have from a service like Ancestry or 23andMe.

If you have data from a blood test on hand, you can also upload that for a physician's review (or, you can order Rootine's blood test). Rootine says it then takes your demographics (age, weight and so on), lifestyle, DNA information and blood analysis into account to create your custom vitamin pack.

Rootine then gives you a detailed profile of all your recommended vitamins, explaining what they do and why the company believes you need them.

A Rootine subscription is $70 a month, regardless of what's in your pack. You're required to purchase a minimum of three months' worth of vitamins, which will be shipped every 90 days but billed monthly. Shipping is free on orders above $45.