Questions Answered: during menopause? can you take it at 16? and with cancer? and...

We've received these questions and think they're really worth sharing. Because this kind of information isn't common knowledge.

“Can my 16-year-old take this?”

A real customer's story (and our honest answers)

“Hi, I've been seeing reels about NR, collagen and ‘miracle’ vitamins for days now. My 16-year-old son plays basketball and wants to perform better. Are they safe? For how long? And what if my mother — who's undergoing cancer treatment — takes them too?”

That's how our customer came to us, with an online basket full of NR (nicotinamide riboside), vitamin C, vitamin D + K, magnesium and collagen with hyaluronic acid. Here's the answer we gave her.

Disclaimer (read this first)

The information in this article is for educational purposes only and does not replace clinical assessment or treatment prescribed by healthcare professionals. Doses, indications and restrictions may vary depending on country, physiological state and concurrent therapies. Before starting, changing or stopping any supplement, consult your doctor or pharmacist and check up-to-date test results. Neither the author nor the company is responsible for improper use of the products mentioned.

Products under review

1. Can a 16-year-old take these?

Supplement	Yes/No?	Quick reason
LifeXpan NR	NO	Only approved for ≥ 18 years and max. 300 mg/day. It wouldn't make much sense anyway, as it raises NAD levels, something we start losing after the age of 30.
Vitamin C	Yes, within 65–75 mg/day (PRI for 15–17 years).
Vitamin D + K	Yes, but D ≤ 100 µg (4,000 IU) UL for 11–17 years.
Magnesium	Yes, AI 300–350 mg/day (10–17 years).	350–425 mg/day for Adults
Collagen + HA	Yes, safety tested up to 10 g/day × 6 months.

Bottom line: for the teenager, everything's fine except the NR: that one stays on the shelf for another two years.

2. For how long?

• Occasional deficiencies → 8–12 weeks followed by a check-up test. If levels normalise, stop and save.

• Collagen/HA → 3-month cycles; if you notice an improvement (less joint pain, better skin), repeat.

• Vitamin D → monitor every autumn-winter (latitude, few hours of sunlight).

• LifeXpan NR (once you turn 30) → 2–3 month blocks with breaks in between.

3. Are there restrictions if there’s cancer in the family?

1. LifeXpan NR: mixed preclinical data. Some models show ↑ metastasis in triple‑negative breast cancer. Extreme caution: only with oncological approval.

2. Antioxidant megadoses (Vit C, D): may interfere with radio/chemotherapy. Only adjust if the deficiency is documented.

3. Vitamin K: care needed if the patient is taking warfarin or another anticoagulant.

4. Magnesium/Collagen: neutral; adjust magnesium if there’s kidney impairment.

4. Are they useful for people with arthritis?

Ingredient	Useful evidence	Straight‑talking summary
Collagen + HA	RCTs and meta‑analyses show ↓ pain and ↑ function in knee osteoarthritis.	May help with symptoms; safe up to 10 g/day.
Vitamin D	2023 meta‑analysis: improves inflammatory markers and pain in RA when there’s a deficiency.	Useful if your 25‑OH‑D levels are low.
Magnesium	Oral supplementation ↓ severity and joint damage in RA models; adequate intake linked to ↓ RA mortality.	Meeting the RDA is cheap and sensible.
LifeXpan NR	Cell/animal studies point to an anti‑inflammatory effect, but there are no clinical trials in humans with arthritis yet.	Promising, but still lab‑bench only.

Clear message: Collagen and the right doses of Vit D and Magnesium = yes; NR doesn’t justify the price tag yet.

5. What about women going through menopause?

Ingredient	What’s it for here?	Quick evidence
Vit D + K	Maintain bone density; reduce fracture risk.	Check your levels and supplement if low.
Collagen + HA	↑ skin elasticity, ↓ wrinkles and joint pain.	5‑10 g/day, 3‑month cycles.
Magnesium	Improves sleep quality and even hot flushes.	300‑350 mg/day; try it for 8 weeks.
LifeXpan NR	Early studies show metabolic and energy improvements in adults 45‑60+.	Still in Phase II; useful if there’s fatigue and budget to spare.

Practical outcome: Collagen for skin and joints, Vit D + K for bones, Magnesium for sleep; NR is optional, not essential.

Tactical conclusion

1. Son (16): Vit C, Vit D + K, Mg, Collagen ✔️; NR ❌ until 18.

2. Arthritis: Collagen, Vit D, Mg = allies; NR still lacks proof.

3. Menopause: Vit D + K for bone, Collagen for skin, Mg for sleep; NR is a “nice extra for the years”.

4. Cancer in progress: Oncologist first, capsules after.

5. Golden rule: Blood tests before Amazon.

References and useful links

1. EFSA NDA Panel. “Nicotinamide riboside chloride as a source of niacin for use in food supplements” (2019). efsa.europa.eu

2. A randomized controlled trial on the efficacy and safety of a food ingredient, collagen hydrolysate, for improving joint comfort

3. EFSA. “Tolerable Upper Intake Level for Vitamin D” (2023).

4. EFSA. “Dietary Reference Values for Vitamin C” (2013).

5. EFSA. “Dietary Reference Values for Magnesium” (2015).

6. Bruyère O. et al. “Efficacy and safety of 10 g/d collagen hydrolysate in knee osteoarthritis: 6‑month RCT” (2009). PubMed ID: 19212858.

7. Dölle C. et al. “NR supplementation and cancer metastasis in TNBC mouse model” Biochem Pharmacol (2023). PubMed ID: 36371959.

8. Collagen peptide vs placebo in knee OA (2023 RCT).

9. Collagen derivatives for osteoarthritis (2024 meta‑analysis).

10. Chen Y. et al. Vit D supplementation in RA meta‑analysis (2023).

11. Franco‑Álvarez A. et al. Oral Mg reduces RA severity (2025).

12. Liu X. et al. Dietary Mg and mortality in RA (2024 cohort).

13. Dietary NAD+ boosters in humans (2024 review).

14. Proksch E. et al. Collagen peptides & skin ageing (2023 systematic).

15. Pereira S. et al. Vit D supplementation in post‑menopause (2023).

16. Flint K. et al. Magnesium‑L‑threonate & sleep (2024 RCT).

(Active links to dig deeper — no excuses).